Exodus 23:16

And the (h) feast of harvest, the firstfruits of thy labours, which thou hast sown in the field: and the (i) feast of ingathering, [which is] in the end of the year, when thou hast gathered in thy labours out of the field.

(h) Which is Whit Sunday, in token that the law was given 50 days after they departed from Egypt.

(i) This is the feast of tabernacles, signifying that they lived for 40 years in the tents or the tabernacles in the wilderness.