The Ritva says the svarah of chazi litztarufai, is the reason the Torah asssered chatzi shiur ( taima d’krah)…. however the issur is learned out from the possuk
The Achiezer learns there are 2 dinim. FROM THE POSSUK OF KOL CHAILEV WE WOULD KNOW THAT THERE IS AN ISSUR…. but not an issur of chailev or nevailah.A stam issur. The svarah of chazi litztarufai tells me that the issur is chailev or nevaila Ayin shum for the nafka mina. ( sorry for the typing, my sec. left early CAUSE OF THE SNOW)