But for the feebler of the flock he did not lay them there: feebler of the flock refers to the animals that are not robust and healthy. They are sometimes described in English as weak, scrawny, or thin. Translators will want to use a term that contrasts with that used in verse 41. Did not lay them means he did not lay the striped branches in the drinking troughs.

So the feebler were Laban’s: the thin, weak animals would tend to produce offspring like their parents and be unaffected by the striped branches. These would remain in Laban’s flocks.

And the stronger Jacob’s: on the other hand the healthier animals would produce offspring of mixed colors and these belonged to Jacob.

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .