Leviticus 23:8

“But ye shall offer an offering made by, fire unto the Lord seven days, etc.] A burnt offering was to be offered unto the Lord on everyone of the seven days, which were two young bullocks, one ram, and seven lambs; besides a meat offering, and a goat for a sin offering, (<042819>Numbers 28:1924); in the seventh day [is] an holy convocation, ye shall do no servile work [therein]; as on the first day, that was on account of the Israelites going out of Egypt; and this is said, on account of Pharaoh and his host being drowned on it; (see Gill on “<021216>Exodus 12:16”).”

“In these verses, the Passover, or Paschal Supper, and the Feast of Unleavened Bread, are plainly spoken of as distinct feasts. See Exodus 12:6, Exodus 12:15, Exodus 12:17; Numbers 28:16-17. Leviticus 23:5 See Exodus 12:6. According to the Hebrew mode of reckoning, the 15th day of the month began on the evening of the 14th. The day of holy convocation with which the Feast of Unleavened Bread commenced Leviticus 23:7 was the 15th, and that with which it terminated was the 21st. Compare Numbers 28:16-17. Leviticus 23:6 Feast - The three festivals (often called the Great Festivals), Passover, Pentecost and tabernacles, to which the name חג chag, i. e. a feast or rejoicing properly belongs…”