Exodus 34:20

20 But the firstling of an ass thou shalt redeem with a lamb: and if thou redeem him not, then shalt thou break his neck . All the firstborn of thy sons thou shalt redeem . And none shall appear before me empty.

Exodus 34:20 In-Context

18 The feast of unleavened bread shalt thou keep . Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month Abib: for in the month Abib thou camest out from Egypt.
19 All that openeth the matrix is mine; and every firstling among thy cattle, whether ox or sheep, that is male .
20 But the firstling of an ass thou shalt redeem with a lamb: and if thou redeem him not, then shalt thou break his neck . All the firstborn of thy sons thou shalt redeem . And none shall appear before me empty.
21 Six days thou shalt work , but on the seventh day thou shalt rest : in earing time and in harvest thou shalt rest .
22 And thou shalt observe the feast of weeks, of the firstfruits of wheat harvest, and the feast of ingathering at the year's end.

Footnotes 1

The King James Version is in the public domain.