Exodus 34:22

19 All that openeth the womb is mine; and all thy cattle that is male, the firstlings of cow and sheep.

20 And the firstling of an ass thou shalt redeem with a lamb: and if thou wilt not redeem it, then thou shalt break its neck. All the first-born 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 plowing time and in harvest thou shalt rest.

22 And thou shalt observe the feast of weeks, [even] of the first-fruits of wheat harvest, and the feast of ingathering at the year`s end.

23 Three times in the year shall all thy males appear before the Lord Jehovah, the God of Israel.

24 For I will cast out nations before thee, and enlarge thy borders: neither shall any man desire thy land, when thou goest up to appear before Jehovah thy God three times in the year.

25 Thou shalt not offer the blood of my sacrifice with leavened bread; neither shall the sacrifice of the feast of the passover be left unto the morning.