Leviticus 23:7

“In the first day ye shall have an holy convocation, etc.] That is, on the first of the seven days of the feast of unleavened bread, even the fifteenth day of the month Nisan; this was separated from the other days of the festival, and more particularly devoted to religions exercises, (see <021216> Exodus 12:16); ye shall do no servile work therein; such as agriculture, or any manufacture or mechanical business, which they and their servants were at other times employed in; but they might bake bread, and boil or roast their meat, and walk abroad, which they might not do on their sabbaths; and therefore it is so expressed as to distinguish it from the work forbidden on that day.”

“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…”

“Num 28:18-25 Leviticus 23:10”