Exodus 23:15-17 Amplified Bible, Classic Edition (AMPC)

¹⁵ You shall keep the Feast of Unleavened Bread; seven days you shall eat unleavened bread as I commanded you, at the time appointed in the month of Abib, for in it you came out of Egypt. None shall appear before Me empty-handed.

¹⁶ Also you shall keep the Feast of Harvest [Pentecost], [acknowledging] the firstfruits of your toil, of what you sow in the field. And [third] you shall keep the Feast of Ingathering [Booths or Tabernacles] at the end of the year, when you gather in the fruit of your labors from the field.

¹⁷ Three times in the year all your males shall appear before the Lord God.