Where does “ĉe” come from?

ĉe (Esperanto) comes from French chez, from Latin casa, from Proto-Indo-European kat- — cub; to weave, to braid; to link or weave...

ĉe (Esperanto): at

Definitions

Step	Language	Word	Meaning
1	French	chez	to, at or in the home, office, etc. of; in;...
2	Latin	casa	hut, cottage, cabin; rural property, small farm;...
3	Proto-Indo-European	kat-	cub; to weave, to braid; to link or weave...

ĉe — Etymology, Origin & Word History | Etymology Explorer