Where does “Иосиф” come from?

Иосиф (Russian) comes from Ancient Greek Ἰωσήφ, from Hebrew יוסף, from Hebrew הוֹסִיף — to add.

Ancestry of “Иосиф”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ἰωσήφ	—
2	Hebrew	יוסף	—
3	Hebrew	הוֹסִיף	to add

Иосиф — Etymology, Origin & Word History | Etymology Explorer