Once, the Cohanim of equal station were running up the ramp (to perform the sacrifice), when one of them caught up with the other in his four ells, took his knife, and thrust it into his heart. R. Tzaddok ascended the steps of the Temple hall and said: It is written (Devarim 21:1) "If there be found a slain one on the earth, etc." Come and let us measure for whom it is incumbent to bring the heifer (of the broken neck) — the Temple or the azarah (the Temple court) — whereupon all of the people burst into tears.
After that the father of the young Cohein came and said to them: "My brothers, let him be your atonement. My son is still palpitating and the (sacrificial) knife has not become unclean" — whereby we are taught that the defilement of knives was of more moment to them than the spilling of blood. And thus is it written (II Kings 21:16) "And Menasheh also shed very much innocent blood until it filled Jerusalem from mouth to mouth."