Where does “Ἁβραῖος” come from?

Ἁβραῖος (Ancient Greek) comes from Ancient Greek -αῖος, from Ancient Greek -ῐος, from Proto-Indo-European -yós — Creates adjectives from noun or verb stems.

Ancestry of “Ἁβραῖος”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	-αῖος	Suffix added to nouns or adjectives, forming adjectives: pertaining to, belonging to ("of")
2	Ancient Greek	-ῐος	belonging to; of”, “belonging to”, “pertaining to
3	Proto-Indo-European	-yós	Creates adjectives from noun or verb stems

Every word from Proto-Indo-European -yós →Every word from Ancient Greek -ῐος →Every word from Ancient Greek -αῖος →