Thy words have upholden him that was falling - That is, either falling into sin, or sinking under calamity and trial. The Hebrew will bear either interpretation, but the connection seems to require us to understand it of one who was sinking under the weight of affliction.
The feeble knees - Margin, "bowing." The knees support the frame. If they fail, we are feeble and helpless. Hence, their being weak, is so often used in the Bible to denote imbecility. The sense is, that Job, in the days of his own prosperity, had exhorted others to submit to God; had counselled them in such a manner as actually to give them support, and that the same views should now have sustained him which he had so successfully employed in comforting others.

Thy words have up, holden him that was falling,.... Or "stumbling" (m); that was stumbling at the providence of God in suffering good men to be afflicted, and wicked men to prosper; which has been the stumbling block of God's people in all ages; see Psalm 73:2; or that was stumbling and falling off from the true religion by reason of the revilings and reproaches of men, and their persecutions for it; which is sometimes the case, not only of nominal professors, Matthew 13:21; but of true believers, though they do not so stumble and fall as to perish: or else being under afflictions themselves, were ready to sink under them, their strength being small; now Job was helped to speak such words of comfort and advice to persons in any and every of these circumstances as to support them and preserve them from failing, and to enable them to keep their place and station among the people of God. The Targum interprets it of such as were falling into sin; the words of good men to stumbling and falling professors, whether into sin, or into affliction by it, are often very seasonable, and very useful, when attended with the power and Spirit of God:
and thou hast strengthened the feeble knees; that were tottering and trembling, and bending, and not able to bear up under the weight of sin, which lay as an heavy burden, too heavy to bear; or of afflictions very grievous and intolerable; to such persons Job had often spoken words that had been useful to alleviate their troubles, and support them under them. It may be observed, that the cases and circumstances of good men in early times were much the same as they are now; that there is no temptation or affliction that befalls the saints but what has been common; and that Job was a man of great gifts, grace, and experience, and had the tongue of the learned, to speak a word in season to every weary soul, in whatsoever condition they were: and all this, so very laudable in him, is not observed to his commendation, but to his reproach; to show that he was not a man of real virtue, that he contradicted himself, and did not act according to his profession and principles, and the doctrines he taught others, and was an hypocrite at heart; though no such conclusion follows, supposing he had not acted according to his principles and former conduct; for it is a difficult thing for any good man to act entirely according to them, or to behave the same in prosperity as in adversity, or to take that advice themselves in affliction, and follow it, they have given to others, and yet not be chargeable with hypocrisy. It would have been much better in Eliphaz and his friends to have made another use of Job's former conduct and behaviour, namely, to have imitated it, and endeavoured to have strengthened, and upheld him in his present distressed circumstances; instead of that, he insults him, as follows.
(m) "offendentem", Cocceius; "impingentem", Drusius, Schmidt, Schultens, Michaelis.

Feeble knees - Such as were weak hearted, and fainting under their trials.