When the desire cometh - The desire comes, it is a tree of life: i. e., the object of our desires is attained. Compare Proverbs 3:18.

Hope deferred maketh the heart sick - When once a good is discovered, want of it felt, strong desire for the possession excited, and the promise of attainment made on grounds unsuspected, so that the reality of the thing and the certainity of the promise are manifest, hope posts forward to realize the blessing. Delay in the gratification pains the mind; the increase of the delay prostrates and sickens the heart; and if delay sickens the heart, ultimate disappointment kills it. But when the thing desired, hoped for, and expected comes, it is a tree of life, עץ חיים ets chaiyim, "the tree of lives;" it comforts and invigorates both body and soul. To the tree of lives, in the midst of the gardens of paradise, how frequent are the allusions in the writings of Solomon, and in other parts of the Holy Scriptures! What deep, and perhaps yet unknown, mysteries were in this tree!

Hope deferred maketh the heart sick,.... That is, the object hoped for; if it is not enjoyed so soon as expected, at least if it is delayed any length of time, the mind becomes uneasy, the heart sinks and fails, and the man is dispirited and ready to despond, and give up all hope of enjoying the desired blessing; whether it be deliverance from any evil, or the possession of any good;
but when the desire cometh, it is a tree of life; when that which is hoped and wished for, and has been long expected and desired, comes; when there is an accomplishment of men's wishes, it is as grateful to him as the tree of life was in Eden's garden; it gives him an unspeakable pleasure and delight. This may be applied to many things in a spiritual way, as to the first coming of Christ; and some have thought this is greatly regarded and chiefly intended; this was the object of the hope of Old Testament saints; and it was hoped for on a good foundation, on the promise of God, which was frequently repeated, enlarged, and confirmed; yet this promised and hoped for blessing was deferred a long time; from the first promise of it to its accomplishment were four thousand years; though not deferred longer than the appointed time, yet longer than the saints expected, and which sometimes made their hearts sick; they became weak and feeble, fearful and dispirited, lest it should never come to pass, which occasioned fresh promises and assurances to them; see Isaiah 35:3, Malachi 3:1; but when "the desire" came, Christ the desired object; and who is desirable for the excellencies of his person, his mediatorial qualifications, the work of redemption and salvation he came about, and the blessings he brought with him; and who is the "desire of all nations" that was to come, Haggai 2:7; it was exceeding joyful and delightful to all that expected him, and were looking for redemption in Israel, or Christ; "the coming desire" (i), as it may be rendered, is "a tree of life", or "lives", the author of life, natural, spiritual, and eternal; see Proverbs 3:18. It may be applied also to the spiritual presence of Christ, and communion with him; this is what believers, being sometimes without, hope and wait for; and sometimes it is deferred a long time, at least they think it so, which makes them very uneasy, and even sick of love, as the church was, Song 5:8; but when what they so earnestly desire is granted them, it is as if they were in Eden's garden, or rather in the paradise above, plucking the fruit of the tree of life: likewise it may be applied to eternal glory and happiness; this is the object of hope in the present state; it is sometimes impatiently expected and desired, and the language of the soul is, "Why is his chariot so long in coming?", "come, Lord Jesus, come quickly", Judges 5:28; and when this desired happiness is enjoyed, how sweet will it be! and the sweeter for having been so much longed and wished for; and when the saints will be in the paradise of God, and eat of the tree of life in the midst of it, and never hunger more.
(i) "desiderium venieus", V. L. Pagninus, Mercerus, Cocceius, Michaelis, Schultens.

The delay of what is anxiously hoped for, is very painful to the mind; obtaining it is very pleasant. But spiritual blessings are chiefly intended.

desire cometh--is realized.
a tree of life--or, "cause of happiness."

The figures of paradise in Proverbs 13:12 and Proverbs 13:14 require us to take along with them the intermediate verse (Proverbs 13:13).
12 Deferred waiting maketh the heart sick,
And a tree of life is a wish accomplished.
Singularly the lxx Κρείσσων ἐναρχόμενος βοηθῶν καρδίᾳ, followed by the Syr. (which the Targ. Transcribes):
(Note: That the Targum of the Proverbs is a Jewish elaboration of the Peshito text, vid., Nldeke in Merx' Archiv, Bd. ii. pp. 246-49.)
Better is he who begins to help than he who remains in hesitating expectation, by which תחלת is doubled, and is derived once from הוחיל, to wait, and the second time from החל, to begin. If the lxx, with its imitators, deteriorates to such a degree proverbs so clear, beautiful, and inviolable, what may one expect from it in the case of those not easily understood! משּׁך signifies also, Isaiah 18:2, to be widely extended (cf. Arab. meshaḳ), here in the sense of time, as נמשׁך, to prolong, Isaiah 13:22, and post-bibl. משׁך הזּמן, the course of time. Regarding תּוחלת, vid., at Proverbs 10:28, where as Proverbs 11:27 תּקות, here תּאוה, as also Psalm 78:29 of the object of the wish, and with בוא in the sense of being fulfilled (cf. Joshua 21:43), as there with הביא in the sense of accomplishing or performing. Extended waiting makes the heart sick, causes heart-woe (מחלה, part. fem. Hiph. of חלה, to be slack, feeble, sick; R. חל, to loosen, to make loose); on the contrary, a wish that has been fulfilled is a tree of life (cf. p. 23), of a quickening and strengthening influence, like that tree of paradise which was destined to renew and extend the life of man.

Hope deferred - Delays in obtaining what a man passionately desires. The desire - The good desired. A tree of life - It is satisfactory, and reviving.