Where does “الفَارِس” come from?

الفَارِس (Andalusian Arabic) comes from Arabic فارس, from Middle Persian 𐭯𐭠𐭫𐭮𐭩, from Old Persian 𐎱𐎠𐎼𐎿, from Proto-Iranian párcuš, from Proto-Indo-Iranian párćuš, from Proto-Indo-European pérḱus — chest; rib.

Ancestry of “الفَارِس”, step by step

Step	Language	Word	Meaning
1	Arabic	فارس	horseman, rider; knight, cavalier; chevalier
2	Middle Persian	𐭯𐭠𐭫𐭮𐭩	Persia
3	Old Persian	𐎱𐎠𐎼𐎿	a Persian
4	Proto-Iranian	párcuš	rib
5	Proto-Indo-Iranian	párćuš	rib
6	Proto-Indo-European	pérḱus	chest; rib

Every word from Proto-Indo-European pérḱus →Every word from Proto-Indo-Iranian párćuš →Every word from Proto-Iranian párcuš →