Acts 2:1 is Pentecost, the day when the fifty days from this verse are completed—the Spirit was poured out.

Deuteronomy 16:9 provides the counting of seven weeks from the start of harvest, exactly the same numbering process described here for the Feast of Weeks.

Exodus 23:14 commands three annual feasts; this verse gives the specific instruction for the Feast of Weeks, one of those three.

Numbers 15:20 also involves a firstfruits offering (dough) like the new grain offering here, but with a different type (heave vs wave).