Where does “חֲדָא” come from?

חֲדָא (Aramaic) comes from Proto-Semitic ʾaḥad- — one.

Ancestry of “חֲדָא”, step by step

Step	Language	Word	Meaning
1	Proto-Semitic	ʾaḥad-	one

חֲדָא — Etymology, Origin & Word History | Etymology Explorer