Where does “色法爾月” come from?

色法爾月 (Chinese) comes from Arabic صَفَر, from Arabic صَفِرَ — to be empty.

Ancestry of “色法爾月”, step by step

Step	Language	Word	Meaning
1	Arabic	صَفَر	—
2	Arabic	صَفِرَ	to be empty

色法爾月 — Etymology, Origin & Word History | Etymology Explorer