Exodus 16:35

Forty years. This statement was either written by Moses shortly before his death or added by an inspired scribe, probably Joshua. In favor of Moses’ authorship is the expression “until they came to a land inhabited,” to which is added, “until they came unto the borders of the land of Canaan.” This need not refer to the crossing of the Jordan, but to the lands east of the Jordan. The author writes exactly as Moses might be expected to have written toward the close of his life. A later writer would have been more specific, and would probably have noted, as Joshua did in his book (Joshua 5:10-12), the exact time when the manna ceased.

Ephah. Equivalent to about 5 gal.