I might think that they (chullin) are subject to (the giving of) breast and thigh (to the Cohein); it is, therefore, written (Ibid.) "as the deer," (whose breast and thigh are not given to the Cohein).
I would then exclude it from breast and thigh, (which do not go to the altar, but to the Cohein); but I would not exclude it from yothereth (the large lobe of the liver) and the two kidneys, (which are sacrificed on the altar in offerings [and they would be forbidden to eat in chullin]); it is, therefore, written "as the hart" (i.e., just as (it is permitted to eat the two kidneys and yothereth of the hart, so, is it permitted to eat those of chullin.)