Leviticus 23:1-6 ESV
The LORD spoke to Moses, saying, “Speak to the people of Israel and say to them, These are the appointed feasts of the LORD that you shall proclaim as holy convocations; they are my appointed feasts.
“Six days shall work be done, but on the seventh day is a Sabbath of solemn rest, a holy convocation. You shall do no work. It is a Sabbath to the LORD in all your dwelling places.
“These are the appointed feasts of the LORD, the holy convocations, which you shall proclaim at the time appointed for them. In the first month, on the fourteenth day of the month at twilight, is the LORD’s Passover. And on the fifteenth day of the same month is the Feast of Unleavened Bread to the LORD; for seven days you shall eat unleavened bread.
ESV: English Standard Version 2016