Where does “רש״י” come from?

רש״י (Hebrew) comes from Hebrew רַבִּי שְׁלֹמֹה יִצְחָקִי.

Ancestry of “רש״י”, step by step

Step	Language	Word	Meaning
1	Hebrew	רַבִּי שְׁלֹמֹה יִצְחָקִי	—

רש״י — Etymology, Origin & Word History | Etymology Explorer