Exodus 23:16

“And the feast of harvest, etc.] This is the second feast, the feast of wheat harvest, between which and barley harvest were fifty days; or between the firstfruits of the one and the first fruits of the other were seven weeks, as Aben Ezra observes, and was sometimes called the feast of weeks; at which feast were to be brought, the first fruits of thy labours, which thou hast sown in the field; the two wave loaves or cakes, made of the first new wheat, which was the effect of their labour in tilling the field, and sowing it with wheat, and reaping it: and the feast of ingathering, [which is] in the end of the year, when thou hast gathered in thy labours out of the field; this is the third…”

“This is the first mention of the three great Yearly Festivals. The feast of Unleavened bread, in its connection with the Paschal Lamb, is spoken of in Exodus 12:0; Exodus 13:0: but the two others are here first named. The whole three are spoken of as if they were familiarly known to the people. The points that are especially enjoined are that every male Israelite should attend them at the sanctuary (compare Exodus 34:23), and that he should take with him an offering for Yahweh, presenting himself before his King with his tribute in his hand. That this condition belonged to all the feasts, though it is here stated only in regard to the Passover, cannot be doubted. See Deuteronomy 16:16.…”

“23:16 The Festival of Harvest was celebrated seven weeks after Passover, around the end of the barley harvest and the beginning of the wheat harvest (mid-May to mid-June). In postbiblical Judaism, this festival commemorated the giving of the Sinai covenant, which was calculated to have occurred fifty days after the first Passover in Egypt (see Lev 23:15-21; Deut 16:9-12). • The Festival of the Final Harvest was celebrated on the fifteenth day of the seventh month of the Hebrew calendar (mid-September to mid-October), after the final harvest of grapes was complete. This festival commemorated the wilderness wanderings when God provided for his people.”

“feast of harvest: Exo 22:29, Exo 34:22; Lev 23:9-21; Num 28:26-31; Deu 16:9-12; Act 2:1 ingathering: Exo 34:22; Lev 23:34-44; Num. 29:12-39; Deu 16:13-15; Neh 8:14-18; Zac 14:16-19; Joh 7:2, Joh 7:37 Exodus 23:17”