Which of you by taking thought,.... As Christ argued before, from the unnecessariness of anxious thoughts and cares, about the provisions of life; so here, from the unprofitableness of them; it being impossible for a man, with all his care and thought, toadd one cubit unto his stature, or "to his age"; so the word is rendered, Joh 9:21 to the days of his life, he is so solicitous about; for a cubit may as well be applied to a man's age, as an "hand's breadth" is to his days, Ps 39:5.
Nor is it so reasonable to think, that Christ should be speaking of making such an addition to a man's height; though that, to be sure, is an impossible thing: since the far greater part of Christ's hearers must be come to their full growth, and could not hope to have any addition made to their height; though they might hope to add to their days; much less such a monstrous one as that of a cubit, and which is a strong reason against the other sense of the word, and for this: for our Lord is speaking of something very small, which men cannot do; as appears from what Luke says, Lu 12:26 "If ye then be not able to do that which is least, why take ye thought for the rest?"
Whereas, to add a cubit to a man's height, is a great deal:"the stature of a middling man (says Bartenora) is three cubits.''And to add one more, makes a large addition to his stature; but to apply this to a man's age, is a small matter, and yet is what men cannot do: the sense of the words is this, that no man, by all the care and thought he can make use of, is ever able to add one cubit, or the least measure to his days; he cannot lengthen out his life one year, one month, one day, one hour; no, not one moment.
In Misn. Erubim, c. 4. sect. 5. & Negaim, c. 13. sect.