Charles Ellicott Commentary Exodus 22:29

"Thou shalt not delay to offer of thy harvest, and of the outflow of thy presses. The first-born of thy sons shalt thou give unto me." — Exodus 22:29 (ASV)

The first of your ripe fruits. —Hebrew, of your fullness. “Firstfruits” were the spontaneous tribute of natural piety among almost all nations. They were called by the Greeks ἀπαρχαί, by the Romans primitive. Abel’s offering (Genesis 4:4) was one of the “firstlings of his flock,” and Cain’s probably one of firstfruits. In the present passage, it is assumed that firstfruits are due, and the stress is placed upon offering them promptly, without “delay.” Delay would show a grudging spirit.

Of your liquors. —As wine and oil. (Nehemiah 10:39.)

The firstborn of your sons. —See the Note on Exodus 13:2; and on the means of redeeming firstborn sons, see Exodus 13:13, and Numbers 17:15, 16.