Leviticus 23:5-6

23:5 In the first month, on the fourteenth day of the month, at twilight, is a Passover offering to the Lord. 23:6 Then on the fifteenth day of the same month will be the festival of unleavened bread to the Lord; seven days you must eat unleavened bread.

Leviticus 23:10

23:10 “Speak to the Israelites and tell them, ‘When you enter the land that I am about to give to you and you gather in its harvest, then you must bring the sheaf of the first portion of your harvest to the priest,

Leviticus 23:12

23:12 On the day you wave the sheaf you must also offer a flawless yearling lamb for a burnt offering to the Lord,