Exodus 13:2

2 aConsecrate to me all the firstborn. Whatever is the first to open the womb among the people of Israel, both of man and of beast, is mine.”

Exodus 13:12

12 byou shall set apart to the Lord all that first opens the womb. All the firstborn of your animals that are males shall be the Lord’s.

Exodus 34:19

19 cAll that open the womb are mine, all your male
Septuagint, Theodotion, Vulgate, Targum; the meaning of the Hebrew is uncertain
livestock, the firstborn of cow and sheep.
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