The Uniform Series text for Sunday, May 13 (Mother’s Day, and also International Women’s Talmud Day) is Leviticus 23:9-14, 22 – a short text on the offering of the first fruits, followed by a verse on gleaning. Here are my [briefer than usual] notes on the text:
Leviticus 23 is a set of instructions for the major festivals, including the three pilgrimage festivals. It begins with Shabbat, includes Passover and the Festival of Unleavened Bread, follows with the offering of firstfruits (vv9-14), and concludes with the Festival of Weeks (or Pentecost, or Shavuot), the Festival of Trumpets and the Day of Atonement, and the Festival of Sukkot.
These days, the second day of Passover, which would have been the day for the firstfruits offering, inaugurates the “counting of the omer” that takes place between Passover and Shavuot/Weeks/Pentecost.
The rabbis understood the location of verse 22, a second instruction about not reaping to the edges of a field or gathering the gleanings, to have special significance. According to Rashi
Rabbi Avdimi the son of Rabbi Joseph says: Why does Scripture place this [passage] in the very middle of [the laws regarding] the Festivals-with Passover and Atzereth (Shavuoth) on one side and Rosh Hashanah, Yom Kippur, and the Festival [of Succoth] on the other? To teach you that whoever gives לֶקֶט, gleanings, שִׁכְחָה, forgotten sheaves, and פֵּאָה, the corners , to the poor in the appropriate manner, is deemed as if he had built the Holy Temple and offered up his sacrifices within it. — [Torath Kohanim 23:175] (online here)
From the standpoint of activity, the people are doing most of the action: entering the land, reaping the harvest, bringing barley, finding acceptance, raising and offering and eating and bringing. The priest’s role is to do the raising of the offering, which seems to have the symbolic significance of placing a protective blessing on the remainder of the harvest.
God, however, has three verbs: The Holy One speaks, gives the land, and is. The land is land God is giving the people who will be doing all that activity. And they will only be doing all that activity because they have entered land that God is giving them.
So it is only appropriate to say “thank you.”
And practically speaking, people do that by providing for the people who depend on their generosity – the gleaners, the priests who conduct the rituals – as everyone ultimately depends on God’s generosity.