Where does “їисъ” come from?

їисъ (Old Church Slavonic) comes from Ancient Greek Ἰησοῦς, from Aramaic ישוע, from Hebrew ישוע, from Hebrew יהושע, from Hebrew הוֹשֵׁעַ — Salvation; Hosea.

Ancestry of “їисъ”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ἰησοῦς	Jesus
2	Aramaic	ישוע	—
3	Hebrew	ישוע	—
4	Hebrew	יהושע	Joshua
5	Hebrew	הוֹשֵׁעַ	Salvation; Hosea

Every word from Hebrew הוֹשֵׁעַ →

їисъ — Etymology, Origin & Word History | Etymology Explorer