Wherefore, when we could no longer endure. By the detail which follows, he assures them of the desire of which he had spoken. For if, on being detained elsewhere, he had sent no other to Thessalonica in his place, it might have seemed as though he were not so much concerned in regard to them; but when he substitutes Timothy in his place, he removes that suspicion, more especially when he prefers them before himself. Now that he esteemed them above himself, he shews from this, that he chose rather to be left alone than that they should be deserted: for these words, we judged it good to be left alone, are emphatic. Timothy was a most faithful companion to him: he had at that time no others with him; hence it was inconvenient and distressing for him to be without him. It is therefore a token of rare affection and anxious desire that he does not refuse to deprive himself of all comfort, with the view of relieving the Thessalonians. To the same effect is the word eudokesamen, which expresses a prompt inclination of the mind. [1]

Footnotes

1 - "Vne affection prompte et procedante d'vn franc coeur;" -- "A prompt disposition, proceeding from a ready mind."

Wherefore - See 1-Thessalonians 2:18. This particle (διὸ dio) is designed here to refer to another proof of his affection for them. One evidence had been referred to in his strong desire to visit them, which he had been unable to accomplish 1-Thessalonians 2:18, and he here refers to another - to wit, the fact that he had sent Timothy to them.
We could no longer forbear - That is, when I could not 1-Thessalonians 3:5, for there is every evidence that Paul refers to himself only though he uses the plural form of the word. There was no one with him at Athens after he had sent Timothy away Acts 17:15; Acts 18:5, and this shows that when, in 1-Thessalonians 2:6, he uses the term apostles in the plural number, he refers to himself only, and does not mean to give the name to Timothy and Silas. If this be so, Timothy and Silas are nowhere called "apostles" in the New Testament. The word rendered here "could forbear" (στέγοντες stegontes), means, properly, "to cover, to conceal;" and then to hide or conceal anger, impatience, weariness, etc.; that is, to hold out as to anything, to bear with, to endure. It is rendered suffer in 1-Corinthians 9:12; beareth, 1-Corinthians 13:7; and forbear, 1-Thessalonians 3:1, 1-Thessalonians 3:5. It is not elsewhere used in the New Testament. It means that he could no longer bear up under, hide, or suppress his impatience in regard to them - his painful emotions - his wish to know of their state; and he therefore sent Timothy to them.
We thought it good - I was willing to suffer the inconvenience of parting with him in order to show my concern for you.
To be left at Athens alone - Paul had been conducted to Athens from Berea, where he remained until Silas and Timothy could come to him; Acts 17:15. It appears from the statement here that Timothy had joined him there, but such was his solicitude for the church at Thessalonica, that he very soon after sent him there, and chose to remain himself alone at Athens. Why he did not himself return to Thessalonica, is not stated. It is evidently implied here that it was a great personal inconvenience for him thus to part with Timothy, and to remain alone at Athens, and that he evinced the strong love which he had for the church at Thessalonica by being willing to submit to it. What that inconvenience consisted in, he has not stated, but it is not difficult to understand,
(1) he was among total strangers, and, when Timothy was gone, without an acquaintance or friend.
(2) the aid of Timothy was needed in order to prosecute the work which he contemplated. He had requested that Timothy should join him as soon as possible when he left Berea Acts 17:15, and he evidently felt it desirable that in preaching the gospel in that city he should have all the assistance he could obtain. Yet he was willing to forego those comforts and advantages in order to promote the edification of the church at Thessalonica.

Wherefore, when we could no longer, etc. - The apostle was anxious to hear of their state, and as he could obtain no information without sending a messenger express, he therefore sent Timothy from Athens; choosing rather to be left alone, than to continue any longer in uncertainty relative to their state.

Wherefore when we could no longer forbear,.... Or "bear", as the word properly signifies; or "bear that", as the Ethiopic version reads; that is, "that desire", as the Arabic version renders it; that ardent and longing desire of seeing them again, expressed in the latter part of the preceding chapter; which was as fire in their bones, and was retained with great pain and uneasiness; but now they could hold it no longer, and like Jeremiah, Jeremiah 20:9 were weary with forbearing, and could not stay; or it was like a burden, which they stood up under as long as they could, even Paul, Silas, and Timothy, but now it became insupportable:
we thought it good to be left at Athens alone: that is, Paul and Silas, or Paul only, speaking of himself in the plural number; for he seems to have been alone at Athens, at least at last; he considering everything, thought it most fit and advisable when at Athens, where he waited for Silas and Timothy, having ordered them to come thither to him from Berea, Acts 17:14 either to send orders to Berea for Timothy to go from thence to Thessalonica, to know the state of affairs there, and Silas elsewhere; or if they came to him to Athens, of which Luke gives no account, he immediately dispatched Timothy to Thessalonica, and Silas to some other part of Macedonia, for from thence they came to him at Corinth, Acts 18:5 such was his desire of knowing how things were at Thessalonica, that he chose rather to be left alone at Athens, disputing with the unbelieving Jews, and Heathen philosophers of the Epicurean and Stoic sects, sustaining all their scoffs and jeers alone; and was content to be without his useful companions, Silas and Timothy, who might have been assisting to him at Athens, in hope of hearing of his dear friends at Thessalonica.

The more we find pleasure in the ways of God, the more we shall desire to persevere therein. The apostle's design was to establish and comfort the Thessalonians as to the object of their faith, that Jesus Christ was the Saviour of the world; and as to the recompence of faith, which was more than enough to make up all their losses, and to reward all their labours. But he feared his labours would be in vain. If the devil cannot hinder ministers from labouring in the word and doctrine, he will, if possible, hinder the success of their labours. No one would willingly labour in vain. It is the will and purpose of God, that we enter into his kingdom through many afflictions. And the apostles, far from flattering people with the expectation of worldly prosperity in religion, told them plainly they must count upon trouble in the flesh. Herein they followed the example of their great Master, the Author of our faith. Christians were in danger, and they should be forewarned; they will thus be kept from being improved by any devices of the tempter.

PROOF OF HIS DESIRE AFTER THEM IN HIS HAVING SENT TIMOTHY: HIS JOY AT THE TIDINGS BROUGHT BACK CONCERNING THEIR FAITH AND CHARITY: PRAYERS FOR THEM. (1-Thessalonians 3:1-13)
Wherefore--because of our earnest love to you (1-Thessalonians 2:17-20).
forbear--"endure" the suspense. The Greek is literally applied to a watertight vessel. When we could no longer contain ourselves in our yearning desire for you.
left at Athens alone--See my Introduction. This implies that he sent Timothy from Athens, whither the latter had followed him. However, the "we" favors ALFORD'S view that the determination to send Timothy was formed during the hasty consultation of Paul, Silas, and Timothy, previous to his departure from Berea, and that then he with them "resolved" to be "left alone" at Athens, when he should arrive there: Timothy and Silas not accompanying him, but remaining at Berea. Thus the "I," 1-Thessalonians 3:5, will express that the act of sending Timothy, when he arrived at Athens, was Paul's, while the determination that Paul should be left alone at Athens, was that of the brethren as well as himself, at Berea, whence he uses, 1-Thessalonians 3:1, "we." The non-mention of Silas at Athens implies that he did not follow Paul to Athens as was at first intended; but Timothy did. Thus the history, Acts 17:14-15, accords with the Epistle. The word "left behind" (Greek) implies that Timothy had been with him at Athens. It was an act of self-denial for their sakes that Paul deprived himself of the presence of Timothy at Athens, which would have been so cheering to him in the midst of philosophic cavillers; but from love to the Thessalonians, he is well content to be left all "alone" in the great city.

When we could no longer forbear. The closing verses of chapter 2 show Paul's great desire to see them, as a father to see his suffering children. Hindered (1-Thessalonians 2:18), he at last "thought it good to be left alone at Athens" (Acts 18:1-5).
And sent Timothy, our brother. Acts 18:5 shows that Paul had been left alone at Athens, went to Corinth alone, and was there joined by Silas and Timothy, who came from Macedonia. Timothy had been sent to strengthen the new church at Thessalonica.
That no man should be moved by these afflictions. Timothy was sent to prevent any one being moved from Christ by the opposition and persecutions suffered.
Yourselves know. Know that it is the lot of God's people to suffer persecution.
For . . . we told you. He had faithfully forewarned them that tribulation would come.
Lest by some means the tempter, etc. The tempter is Satan. Unable to hear from them, fearing the effect of their fiery trial, he sent Timothy, not only to strengthen them, but to report to him their state.

We - Paul and Silvanus. Could bear no longer - Our desire and fear for you.