This 3rd feast starts on the 2nd day of the Feast of Unleavened Bread. "First Fruits," according to Jewish understanding, occurs on the 16th day of the Hebrew month, “Nissan”. It is the first crop planted in winter, the barley harvest. The first fruits of the harvest is cut and, in a prescribed ceremony, presented to the Lord (Leviticus 23:9 – 14).
Another name for this feast is called "Yom HaBikkurim". It also starts the "Sfirat Haomer" – the counting of the sheaf. The one word connected to this feast is "Resurrection". The Lord's acceptance of the first fruits is a “pledge” or “down payment” on his part for the full harvest or resurrection (Ephesians 1:14)