Rashi on Genesis 22:6/רש"י על בראשית כ״ב:ו׳

1המאכלת — means a knife. It is called מאכלת from אכל to eat, because it devours the meat, — just as you say, (Deuteronomy 32:42 “And my sword shall devour (תאכל) flesh”— or because it makes animal flesh fit for eating (מאכלת) (by killing the animal; because while the animal is living its flesh is unfit for eating). Another explanation: זאת נקראת This knife is called מאכלת (and the term is never used of an ordinary knife) because Israel still eats of the reward given for it (Genesis Rabbah 56:3).

2וילכו שניהם יחדיו AND THEY WENT BOTH OF THEM TOGETHER — Abraham who was aware that he was going to slay his son walked along with the same willingness and joy as Isaac who had no idea of the matter.