Moses
Leviticus 23:20ESV·traditional attribution

And the priest shall wave them with the bread of the firstfruits as a wave offering before the LORD, with the two lambs. They shall be holy to the LORD for the priest.

Matthew Henry Presbyterian

Here is the institution of the feast of pentecost, or weeks, as it is called (Deu 16:9), because it was observed fifty days, or seven weeks, after the passover. It is also called the feast of harvest, Exo 23:16. For as the presenting of the sheaf of first-fruits was an introduction to the harvest, and gave them liberty to put in the sickle, so they...

Commenting on Leviticus 23:15-22

John Gill Reformed Baptist

And the priests shall wave them with the bread of the firstfruits,.... The two loaves called the two wave loaves, Lev 23:17; with which were waved the two lambs of the peace offerings; and these alive, as Jarchi and Ben Gersom intimate.

Jamieson-Fausset-Brown Reformed

FEAST OF PENTECOST. (Lev 23:15-22) ye shall count unto you from the morrow after the sabbath--that is, after the first day of the passover week, which was observed as a Sabbath.

Commenting on Leviticus 23:15-22