Ye shall offer up a cake of the first of your dough [for] an heave offering,.... Of the first dough made of the first corn that was threshed, winnowed and ground, they were to make a cake, and offer it an heave offering unto the Lord; the quantity of it is not expressed, but was left to the people's generosity; no stinted measure was fixed by the law; but according to the Scribes, or the traditions of the elders, the quantity of the cake was the twenty fourth part of the first dough that was kneaded; not the forty fourth, as Buxtorf p through mistake says; so the Targum of Jonathan,
"of the first of your dough, one out of twenty four (i.e. the twenty fourth part of it), ye shall separate a separation for the priests,''
with which agrees the Misnah q, though according to that, if made to sell publicly it was the forty eighth part of it. Some, because
Numbers 15:21 begins and ends with מ, "mem", which numerically signifies "forty", think this is an instruction to a bountiful person to give the fortieth part r:
as [ye do] the heave offering of the threshing floor, so shall ye heave it; as the two wave loaves and firstfruits of their harvest,
p Synagog. Jud. c. 34. p. 602. q Challah, c. 2. sect. 7. so Schulchan Aruch, par. 2. c. 322. so Jarchi & Ben Gersom in loc. r Baal Hatturim in loc.