Where does “čstíti” come from?

čstíti (Old Czech) comes from Proto-Slavic čьstiti, from Proto-Indo-European (s)kʷit-tis.

Ancestry of “čstíti”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	čьstiti	—
2	Proto-Indo-European	(s)kʷit-tis	—

čstíti — Etymology, Origin & Word History | Etymology Explorer