Where does “of” come from?

of (Middle English) comes from Old English of, from Old English æf, from Proto-Germanic *ab, from Proto-Indo-European apó.

of (Middle English): of; off; until

Definitions

of traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Old English	of	of, from, off, out of
2	Old English	æf	of
3	Proto-Germanic	*ab	—
4	Proto-Indo-European	apó	—

Step	Language	Word	Meaning
1	Middle English	thof	—
2	Old English	þēah	though, although, even if, that, however,...