Augustine of Hippo
Catena Aurea · Matthäusevangelium 19
And, behold, one came and said unto him, Good Master, what good thing shall I do, that I may have eternal life? And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments. He saith unto him, Which? Jesus said, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness, Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself. The young man saith unto him, All these things have I kept from my youth up: what lack I yet? Jesus said unto him, If thou wilt be perfect, go and sell that thou hast, and give to the poor, and thou shalt have treasure in heaven: and come and follow me. But when the young man heard that saying, he went away sorrowful: for he had great possessions.
(de Trin. i. 13.) Or, because he sought eternal life, (and eternal life consists in such contemplation in which God is beheld not for punishment, but for everlasting joy,) and knew not with whom he spake, but thought Him only a Son of Man, therefore He says, Why askest thou me concerning good, calling me in respect of what you see in me, Good Master? This form of the Son of Man shall appear in the judgment, not to the righteous only, but to the wicked, and the very sight shall be to them an evil, and their punishment. But there is a sight of My form, in which I am equal to God. That one God therefore, Father, Son, and Holy Spirit, is alone good, because none see Him to mourning and sorrow, but only to salvation and true joy.