Ambrose of Milan — as excerpted in the Catena Aurea on Luke 18:18-23

“He does not deny that He is good, but points to God. None is good then except he be full of goodness. But should it strike any one that it is said, none is good, let this also strike him, save God, and if the Son is not excepted from God, surely neither is Christ excepted from good. For how is He not good who is born from good? A good tree brings forth good fruits. (Matt. 7:17.) How is He not good, seeing that the substance of His goodness which He took unto Him from the Father has not degenerated in the Son which did not degenerate in the Spirit. Thy good spirit, he says, shall lead me into a land of uprightness. (Ps. 148:10.) But if the Spirit is good who received from the Son, verily He also is good who gave It. Because then it was a lawyer who tempted Him, as is plainly shewn in another book, He therefore well said, None is good, save God, that He might remind him that it was written, Thou shalt not tempt the Lord thy God, (Deut. 6:16.) but he the rather gives thanks to the Lord that He is good. (Ps. 118.)”