Genesis 46:18

Muppim, and Huppim, and Ard; in all one hundred and ten. It is a difficulty to account for it, that Benjamin, Jacob's youngest son, often called a lad at this time, and generally supposed to be about twenty three or four years of age, should have so many sons: some think he had more wives than one, which is not likely, since we never read of any of Jacob's sons that had more than one at a time; and others, that his sons were born twins, and so had them in a little time, which is a much better solution of the difficulty: but others are of opinion, that though the greater part of them might be born in Canaan, yet others might be born in Egypt; and being denominated from the greater part, and that being put for the whole, may be reckoned among the descendants into Egypt; and even those that were in Egypt, being born while Jacob was alive, might be said to descend there in his loins; which may be the best of the ways proposed for removing this difficulty: though I should rather think they were all born before the descent into Egypt, the whole narrative seems to require this of them all; for otherwise many more might be, said to descend in the loins of Jacob, or in the loins of his sons, which would greatly increase the number of those said to go down with him, after mentioned: to which it may be added, that Benjamin was at least thirty two years of age, and so may very well be thought to have had these children before he went to Egypt.