Of the first of your dough shall ye give unto the Lord,.... As an acknowledgment of his being the sovereign Lord and possessor of heaven and earth, and of his being the owner and proprietor of the land of Canaan; and by way of thankfulness to him for the plenty of bread corn he had given them; and wherefore this cake was to he heaved or lifted up towards him in heaven, as follows:an heave offering in your generations: for this respected not only the first time of their entrance into the land of Canaan, but was to be observed every year when they made their first dough, and was to continue as long as the ceremonial law lasted: this cake was anciently given to the priest, which is meant by giving it to the Lord, but now the Jews take it and cast it into the fire and burn it the apostle seems to allude to this cake of the first dough in Ro 11:16.
Buxtorf. ut supra, (Synagog. Jud. c. 34. p. 602.) & Leo Modena, History of the present Jews, par. 2. c.