Verses 19-20 are quite similar to 13.12-13. All that opens the womb is mine is discussed at 13.2. It is simply a technical expression for the firstborn. All your male cattle presents some textual difficulty. Literally the Hebrew says “and all your [singular] livestock she is remembered,” which does not make much sense. With a slight change of one letter, the text can be made to read “and all your livestock the male,” and this is what the ancient versions have. (See the Revised Standard Version footnote.) This is also suggested by the context and the similar verses in chapter 13. The same word for cattle is used in 9.3. (See the comment there.)

The firstlings of cow and sheep uses the technical term that means “what opens a mother’s womb.” It means the same as “first-born” (Good News Translation). The Hebrew word for cow often refers specifically to a full-grown male bovine, or ox, but here the broader meaning of large domesticated animal is intended. The word for sheep actually includes both sheep and goats. It is usually used in reference to the flock, which included both animals. New Jerusalem Bible correctly has “every first-born of flock or herd.”

The first part of the verse is probably a general statement that includes the sons of the Israelites as well as their animals. So Good News Translation condenses the whole verse, “Every first-born son and first-born male domestic animal belongs to me.” Contemporary English Version has “The first-born males of your families and your flocks and herds belong to me.”

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .