19:17 Why callest thou me good - Whom thou supposest to be only a man. There is none good - Supremely, originally, essentially, but God. If thou wilt enter into life, keep the commandments - From a principle of loving faith. Believe, and thence love and obey. And this undoubtedly is the way to eternal life. Our Lord therefore does not answer ironically, which had been utterly beneath his character, but gives a plain, direct, serious answer to a serious question.

Matthew 19:17 Parallel Commentaries

The Way.
If thou wouldest be perfect.'--ST. MATTHEW xix 21. For reasons many and profound, amongst the least because of the fragmentary nature of the records, he who would read them without the candle of the Lord--that is, the light of truth in his inward parts-- must not merely fall into a thousand errors--a thing for such a one of less moment--but must fail utterly of perceiving and understanding the life therein struggling to reveal itself--the life, that is, of the Son of Man, the thought, the feeling, …
George MacDonald—Unspoken Sermons

A Treatise on Good Works
I. We ought first to know that there are no good works except those which God has commanded, even as there is no sin except that which God has forbidden. Therefore whoever wishes to know and to do good works needs nothing else than to know God's commandments. Thus Christ says, Matthew xix, "If thou wilt enter into life, keep the commandments." And when the young man asks Him, Matthew xix, what he shall do that he may inherit eternal life, Christ sets before him naught else but the Ten Commandments. …
Dr. Martin Luther—A Treatise on Good Works

Journey to Jerusalem. Concerning Divorce.
^A Matt. XIX. 1-12; ^B Mark X. 1-12. ^a 1 And it came to pass when Jesus had finished these words [the words contained in Matt. xviii., which are the last teachings in Galilee recorded by any of the Evangelists, p. 435 and p. 439 he departed from Galilee [Having come into the borders of it again from Ephraim. It seems likely that Matthew takes in at one view both departures from Galilee, viz.: that mentioned on p. 441 and that at [4]Sec. XCV., for Matthew records none of the intervening events and …
J. W. McGarvey—The Four-Fold Gospel