Where does “Iafeth” come from?

Iafeth (Old English) comes from Latin Iaphet, from Koine Greek Ἰάφεθ, from Hebrew יֶפֶת.

Ancestry of “Iafeth”, step by step

Step	Language	Word	Meaning
1	Latin	Iaphet	—
2	Koine Greek	Ἰάφεθ	—
3	Hebrew	יֶפֶת	—