Where does “תְּלָתָא” come from?

תְּלָתָא (Aramaic) comes from Proto-Semitic ṯalāṯ- — three.

Ancestry of “תְּלָתָא”, step by step

Step	Language	Word	Meaning
1	Proto-Semitic	ṯalāṯ-	three

תְּלָתָא — Etymology, Origin & Word History | Etymology Explorer