Where does “sī vīs” come from?

sī vīs (Latin) comes from Latin vīs, from Proto-Italic wīs, from Proto-Indo-European wéyh₁s, from Proto-Indo-European weyh₁- — to chase, pursue; to suppress, persecute.

sī vīs (Latin): (a parenthetical remark) if you please

Definitions

(a parenthetical remark) if you please

Ancestry of “sī vīs”, step by step

sī vīs traces back through two separate lines of ancestry.

via Latin vīs

Step	Language	Word	Meaning
1	Latin	vīs	force
2	Proto-Italic	wīs	strength, force, power
3	Proto-Indo-European	wéyh₁s	force, vehemence
4	Proto-Indo-European	weyh₁-	to chase, pursue; to suppress, persecute

via Latin sī

Step	Language	Word	Meaning
1	Latin	sī	if, supposing that
2	Proto-Italic	sei	so, thus
3	Proto-Indo-European	só	this; that

Every word from Proto-Indo-European weyh₁- →Every word from Proto-Indo-European wéyh₁s →Every word from Proto-Italic wīs →