Where does “σεραφείμ” come from?

σεραφείμ (Koine Greek) comes from Hebrew שְׂרָפִים, from Hebrew שָׂרָף — venomous snake; seraph.

Ancestry of “σεραφείμ”, step by step

Step	Language	Word	Meaning
1	Hebrew	שְׂרָפִים	—
2	Hebrew	שָׂרָף	venomous snake; seraph