Where does “ישעיהו” come from?

ישעיהו (Hebrew) comes from Hebrew ־יהו, from Hebrew יהוה, from Proto-Semitic *haway-.

Ancestry of “ישעיהו”, step by step

Step	Language	Word	Meaning
1	Hebrew	־יהו	A theophoric suffix, meaning "the Lord", used in...
2	Hebrew	יהוה	YHWH, Yahweh, Jehovah; God; Yahweh
3	Proto-Semitic	*haway-	—

ישעיהו — Etymology, Origin & Word History | Etymology Explorer