'Unleavened' in the Bible

He observed the daily requirements for sacrifices that Moses had specified for Sabbaths, new moon festivals, and the three annual celebrations -- the Feast of Unleavened Bread, the Feast of Weeks, and the Feast of Temporary Shelters.

A huge crowd assembled in Jerusalem to observe the Feast of Unleavened Bread in the second month.

The Israelites who were in Jerusalem observed the Feast of Unleavened Bread for seven days with great joy. The Levites and priests were praising the Lord every day with all their might.

So the Israelites who were present observed the Passover at that time, as well as the Feast of Unleavened Bread for seven days.