Wave offerings

parts of peace-offerings were so called, because they were waved
by the priests (Ex. 29:24, 26, 27; Lev. 7:20-34; 8:27; 9:21;
10:14, 15, etc.), in token of a solemn special presentation to
God. They then became the property of the priests. The
first-fruits, a sheaf of barley, offered at the feast of
Pentecost (Lev. 23:17-20), and wheat-bread, the first-fruits of
the second harvest, offered at the Passover (10-14), were
wave-offerings.