Why is a Shochet’s Knife Called a Chalaf ?

Whom did you hear saying that the place between Hall and altar was [considered] north? R. Eleazar son of R. Simeon, for it was taught: What is [considered] north? From the northern wall of the altar up to the [northern] wall of the Temple court and opposite the whole altar on the north, this is the opinion of R. Jose son of R. Judah. R. Eleazar son of R. Simeon adds also the space between the Hall and the altar. Rabbi adds also the space for the treading of the priests and the place for the treading of the Israelites within, and all agree, min ha’chalifos, that from the inside of the knives’ cell it was illegitimate.
--Yoma 36a

This remaining space is called beis ha’chalifos…because they stored the holy knives there and a sakin, a knife, is called chiluf in Arabic…
--Rashi Yoma 36a

I once saw a source which said a shochet’s knife is called a chalaf because it changes, cholef, the state of the animal from life to death. Does anyone know the source for this explanation?

Story on shochet’s knives: I was once boarding a plane and security stopped an Israeli shochet who spoke English poorly. Security found a chalaf in his bag and asked him what this was about? He said, “I am a killer.” In the midst of the commotion that followed, he asked me to help explain it to security.