Now when he was in Jerusalem at the passover, in the feast day, many believed in his name, when they saw the miracles which he did.
All Commentaries on John 2:23 Go To John 2
John Chrysostom
AD 407
Those had been wiser disciples, however, who were brought to Christ not by His miracles, but by His doctrine. For it is the duller sort who are attracted by miracles; the more rational are convinced by prophecy, or doctrine. And therefore it follows, But Jesus did not commit Himself to them.
Or it means that He did not place confidence in them, as perfect disciples, and did not, as if they were brethren of confirmed faith, commit to them all His doctrines, for He did not attend to their outward words, but entered into their hearts, and well knew how short-lived was their zeal. Because He knew all men, and needed not that any should testify of man, for He knew what was in man. To know what is in man’s heart, is in the power of God alone, who fashioned the heart. He does not want witnesses, to inform Him of that mind, which was of His own fashioning.