Surety - The "pledge," or security for payment, which, for example, David was to bring back from his brothers 1-Samuel 17:18. So the word was used in the primitive trade transactions of the early Israelites.
In the warnings against this suretyship, in the Book of Proverbs, we may trace the influence of contact with the Phoenicians. The merchants of Tyre and Zidon seem to have discovered the value of credit as an element of wealth. A man might obtain goods, or escape the pressure of a creditor at an inconvenient season, or obtain a loan on more favorable terms, by finding security. To give such security might be one of the kindest offices which one friend could render to another. Side by side, however, with a legitimate system of credit there sprang up, as in later times, a fraudulent counterfeit. Phoenician or Jewish money-lenders (the "stranger") were ready to make their loans to the spendthrift. He was equally ready to find a companion (the "friend") who would become his surety. It was merely a form, just writing a few words, just "a clasping of the hands" (see the marginal reference) in token that the obligation was accepted, and that was all. It would be unfriendly to refuse. And yet, as the teacher warns his hearers, there might be, in that moment of careless weakness, the first link of a long chain of ignominy, galling, fretting, wearing, depriving life of all its peace. The Jewish law of debt, hard and stern like that of most ancient nations, aright be enforced against him in all its rigour. Money and land might go, the very bed under him might be seized, and his garment torn from his back Proverbs 20:16; Proverbs 22:27, the older and more lenient law Exodus 22:25-27 having apparently fallen into disuse. he might be brought into a life-long bondage, subject only to the possible relief of the year of jubilee, when the people were religious enough to remember and observe it. His wives, his sons, his daughters might be sharers in that slavery Nehemiah 5:3-5. It was doubtful whether he could claim the privilege which under Exodus 21:2 belonged to an Israelite slave that had been bought. Against such an evil, no warnings could be too frequent or to urgent.
Stricken thy hand - The natural symbol of the promise to keep a contract; in this case, to pay another man's debts. Compare Proverbs 17:18; Proverbs 22:26; Job 17:3; Ezekiel 17:18.

If thou be surety for thy friend - לרעך lereacha, for thy neighbor; i.e., any person. If thou pledge thyself in behalf of another, thou takest the burden off him, and placest it on thine own shoulders; and when he knows he has got one to stand between him and the demands of law and justice, he will feel little responsibility; his spirit of exertion will become crippled, and listlessness as to the event will be the consequence. His own character will suffer little; his property nothing, for his friend bears all the burden: and perhaps the very person for whom he bore this burden treats him with neglect; and, lest the restoration of the pledge should be required, will avoid both the sight and presence of his friend. Give what thou canst; but, except in extreme cases, be surety for no man. Striking or shaking hands when the mouth had once made the promise, was considered as the ratification of the engagement; and thus the man became ensnared with the words of his mouth.

My son, if thou be surety for thy friend,.... To another; hast engaged thyself by promise or bond, or both, to pay a debt for him, if he is not able, or if required; or hast laid thyself under obligation to any, to see the debt of another paid;
if thou hast stricken thy hand with a stranger; or "to" him (b); whom thou knowest not, and to whom thou owest nothing; and hast given him thine hand upon it, as well as thy word and bond, that what such an one owes him shall be paid; a gesture used in suretyship for the confirmation of it, Proverbs 17:18; or, "for a stranger" (c) And the sense is, either if thou art become bound for a friend of thine, and especially if for a stranger thou knowest little or nothing of, this is a piece of rashness and weakness; or, as Gersom, if thou art a surety to thy friend for a stranger, this also is a great inadvertency and oversight. It is a rash and inconsiderate entering into suretyship that is here cautioned against; doing it without inquiring into, and having sufficient knowledge of the person engaged for; and without considering whether able to answer the obligation, if required, without hurting a man's self and family; otherwise suretyship may lawfully be entered into, and good be done by it, and no hurt to the surety himself and family. Jarchi interprets it of the Israelites engaging themselves to the Lord at Sinai, to keep his commandments.
(b) "extraneo", Pagninus, Montanus, Junius & Tremellius, Piscator, Baynus, Mercerus, Gejerus, Cocceius, Schultens. (c) "Proverbs alieno", Tigurine version; "pro alio peregrino", Michaelis.

If we live as directed by the word of God, we shall find it profitable even in this present world. We are stewards of our worldly substance, and have to answer to the Lord for our disposal of it; to waste it in rash schemes, or such plans as may entangle us in difficulties and temptations, is wrong. A man ought never to be surety for more than he is able and willing to pay, and can afford to pay, without wronging his family; he ought to look upon every sum he is engaged for, as his own debt. If we must take all this care to get our debts to men forgiven, much more to obtain forgiveness with God. Humble thyself to him, make sure of Christ as thy Friend, to plead for thee; pray earnestly that thy sins may be pardoned, and that thou mayest be kept from going down to the pit.

After admonitions against suretyship and sloth (compare Proverbs 6:6-8), the character and fate of the wicked generally are set forth, and the writer (Proverbs. 6:20-35) resumes the warnings against incontinence, pointing out its certain and terrible results. This train of thought seems to intimate the kindred of these vices. (Proverbs. 6:1-35)
if--The condition extends through both verses.
be surety--art pledged.
stricken . . . hand--bargained (compare Job 17:3).
with a stranger--that is, for a friend (compare Proverbs 11:15; Proverbs 17:18).

The author warns against suretyship; or rather, he advises that if one has made himself surety, he should as quickly as possible withdraw from the snare.
1 My son, if thou hast become surety for thy neighbour,
Hast given thy hand for another:
2 Thou art entangled in the words of thy mouth,
Ensnared in the words of thy mouth.
3 Do this then, my son, and free thyself -
For thou hast come under the power of thy neighbour -
Go, instantly entreat and importune thy neighbour.
4 Give no sleep to thine eyes,
And no slumber to thine eyelids;
5 Tear thyself free like a gazelle from his hand,
And as a bird from the hand of the fowler.
The chief question here is, whether ל after ערב introduces him for whom or with whom one becomes surety. Elsewhere ערב (R. רב, whence also ארב, nectere, to twist close and compact) with the accusative of the person means to become surety for any one, to represent him as a surety, Proverbs 11:15; Proverbs 20:16 (Proverbs 27:13), Genesis 43:9; Genesis 44:33 (as with the accusative of the matter, to pledge anything, to deposit it as a pledge, Jeremiah 30:21; Nehemiah 5:3, = שׂים, Arab. waḍ'a, Job 17:3); and to become surety with any one is expressed, Genesis 17:18, by ערב לפני. The phrase ערב ל is not elsewhere met with, and is thus questionable. If we look to Proverbs 6:3, the רע (רעה) mentioned there cannot possibly be the creditor with whom one has become surety, for so impetuous and urgent an application to him would be both purposeless and unbecoming. But if he is meant for whom one has become surety, then certainly לרעך is also to be understood of the same person, and ל is thus dat. commodi; similar to this is the Targumic ערבוּתא על, suretyship for any one, Proverbs 17:18; Proverbs 22:26. But is the זר, 1b, distinguished from רעך, the stranger with whom one has become surety? The parallels Proverbs 11:15; Proverbs 20:16, where זר denotes the person whom one represents, show that in both lines one and the same person is meant; זר is in the Proverbs equivalent to אחר, each different from the person in the discourse, Proverbs 5:17; Proverbs 27:2 - thus, like רעך, denotes not the friend, but generally him to whom one stands in any kind of relation, even a very external one, in a word, the fellow-creatures or neighbours, Proverbs 24:28 (cf. the Arab. sahbk and ḳarynk, which are used as vaguely and superficially). It is further a question, whether we have to explain 1b: if thou hast given thine hand to another, or for another. Here also we are without evidence from the usage of the language; for the phrase תּקע כּף, or merely תּקע, appears to be used of striking the hand in suretyship where it elsewhere occurs without any further addition, Proverbs 17:18; Proverbs 22:26; Proverbs 11:15; however, Job 17:3, נתקע ליד appears the same: to strike into the hand of any one, i.e., to give to him the hand-stroke. From this passage Hitzig concludes that the surety gave the hand-stroke, without doubt in the presence of witnesses, first of all of the creditor, to the debtor, as a sign that he stood for him. But this idea is unnatural, and the "without doubt" melts into air. He on whose hand the stroke falls is always the person to whom one gives suretyship, and confirms it by the hand-stroke. Job also, l.c., means to say: who else but Thou, O Lord, could give to me a pledge, viz., of my innocence? If now the זר, v. 1b, is, as we have shown, not the creditor,
(Note: A translation by R. Joseph Joel of Fulda, 1787, whose autograph MS Baer possesses, renders the passage not badly thus: - "My son, if thou hast become surety for thy friend, and hast given the hand to another, then thou art bound by thy word, held by thy promise. Yet do what I say to thee, my son: Be at pains as soon as thou canst to get free, otherwise thou art in the power of thy friend; shun no trouble, be urgent with thy friend.")
but the debtor, then is the ל the dat. commodi, as 1a, and the two lines perfectly correspond. תּקע properly means to drive, to strike with a resounding noise, cogn. with the Arab. wak'a, which may be regarded as its intrans. (Fl.); then particularly to strike the hand or with the hand. He to whom this hand-pledge is given for another remains here undesignated. A new question arises, whether in Proverbs 6:6, where נוקשׁ (illaqueari) and נלכּד (comprehendi) follow each other as Isaiah 8:15, cf. Jeremiah 50:24, the hypothetical antecedent is continued or not. We agree with Schultens, Ziegler, and Fleischer against the continuance of the אם. The repetition of the בּאמרי פיך (cf. Proverbs 2:14) serves rightly to strengthen the representation of the thought: thou, thou thyself and no other, hast then ensnared thyself in the net; but this strengthening of the expression would greatly lose in force by placing Proverbs 6:2 in the antecedent, while if Proverbs 6:2 is regarded as the conclusion, and thus as the principal proposition, it appears in its full strength.

Surety - Rashly, without considering how thou shalt discharge the debt as occasion require. Otherwise suretyship in some cases may be not only lawful, but an act of justice and charity. Stricken thy hand - Obliged thyself by giving thine hand, as the custom then was in such cases. With - With the creditor, whom he calls a stranger, because the usurers in Israel, who lent money to others, upon condition of paying use for it, were either Heathens, or were reputed as bad as Heathens, because this practice was forbidden by God's law, Deuteronomy 23:19.