The Literal Commandment
Then on the fifteenth day of the same month there is the Feast of Unleavened Bread to the LORD; for seven days you shall eat unleavened bread. On the first day you shall have a holy convocation; you shall not do any laborious work. (Leviticus 23:7)
The literal commandment is that we should not do any laborious work on the first day of the Feast of Unleavened Bread.