Exodus 23:14-17

14Thrice in the year thou shalt celebrate a feast to me.

15Thou shalt keep the feast of unleavened bread, (thou shalt eat unleavened bread seven days, as I have commanded thee, in the time appointed of the month Abib; for in it thou camest out from Egypt; and none shall appear in my presence empty;)

16and the feast of harvest, the first-fruits of thy labours which thou hast sown in the field, and the feast of in-gathering, at the end of the year, when thou gatherest in thy labours out of the field.

17Three times in the year all thy males shall appear in the presence of the Lord Jehovah.