Where does “南無阿彌陀佛” come from?

南無阿彌陀佛 (Chinese) comes from Sanskrit नमोऽमिताभाय.

Ancestry of “南無阿彌陀佛”, step by step

Step	Language	Word	Meaning
1	Sanskrit	नमोऽमिताभाय	—

南無阿彌陀佛 — Etymology, Origin & Word History | Etymology Explorer