Like his elder namesakes, he was a recognized authority on halakhah; but in aggadah he surpassed them, being by far the most frequently quoted by aggadists of his own times and of subsequent generations.
Commenting onAbraham's attempt to sacrificeIsaac, Aḥa tries to prove that the patriarch misunderstood the divine call. He refers to the verse "My covenant will I not break, nor alter the thing that is gone out of my lips,"[5] which he construes thus:
My covenant will I not break, even that covenant in which I have assured Abraham: "In Isaac shall your seed be called",[6] nor alter the thing which is gone out of my lips, when I said to him, "Take now your son".[7] This may be compared to a king who told his friend to place his son on his table. The friend returned with his own child and with a knife in hand. The king exclaimed, "Did I ask you to bring him up to eat? I said to bring him up, because he is loved." Similarly, said the Holy One—blessed be He!—to Abraham: 'Take now thy son, and offer him there for a burnt offering;' whereupon Abraham built an altar, and placed his son upon it. But when he stretched forth his hand for the knife, the angel cried out, 'Lay not thine hand upon the youth.' And when Abraham inquired, 'Didst thou not tell me to offer my son?' the angel retorted, 'Did I tell thee to kill him?'[8]
This article incorporates text from a publication now in thepublic domain: Singer, Isidore; et al., eds. (1901–1906)."AḤA (AḤAI) III.".The Jewish Encyclopedia. New York: Funk & Wagnalls.