The naive reason he gives for not obeying--namely, his never having done as he was now bid to do--is charmingly illogical and human. God tells him to do a new thing, and his reason for not doing it is that it is new. Use and wont are set up by us all against the fresh disclosures of God's will. The command to kill and eat was not repeated. It was but the introduction to the truth which was repeated thrice, the same number of times as Peter had denied his Master and had received his charge to feed His sheep.
That great truth has manifold applications, but its direct purpose as regards Peter is to teach that all restrictions which differentiated Jew from Gentile are abolished. 'Cleansing' does not here apply to moral purifying, but to the admission of all mankind to the same standing as the Jew. Therefore the Gospel is to be preached to all men, and the Jewish Christian has no pre-eminence.
Peter's perplexity as to the meaning of the vision is very intelligible. It was not so plain as to carry its own interpretation, but, like most other of God's teachings, was explained by circumstances. What was next done made the best commentary on what had just been beheld. While patient reflection is necessary to do due honour to God's teachings and to discover their bearing on events, it is generally true that events unfold their significance as meditation alone never can. Life is the best commentator on God's word. The three men down at the door poured light on the vision on the housetop. But the explanation was not left to circumstances. The Spirit directed Peter to go with the messengers, and thus taught him the meaning of the enigmatical words which he had heard from heaven.
It is to be remembered that the Apostle had no need of fresh illumination as to the world-wide preaching of the Gospel. Christ's commission to 'the uttermost parts of the earth' ever rang in his ears, as we may be sure. But what he did need was the lesson that the Gentiles could come into the Church without going through the gate of Judaism. If all peculiar sanctity was gone from the Jew, and all men shared in the 'cleansing,' there was no need for keeping up any of the old restrictions, or insisting on Gentiles being first received into the Israelitish community as a stage in their progress towards Christianity.
It took Peter and the others years to digest the lesson given on the housetop, but he began to put it in practice that day. How little he knew the sweep of the truth then declared to him! How little we have learned it yet! All exclusiveness which looks down on classes or races, all monkish asceticism which taboos natural appetites and tastes, all morbid scrupulosity which shuts out from religious men large fields of life, all Pharisaism which says 'The temple of the Lord are we,' are smitten to dust by the great words which gather all men into the same ample, impartial divine love, and, in another aspect, give Christian culture and life the charter of freest use of all God's fair world, and place the distinction between clean and unclean in the spirit of the user rather than in the thing used. 'Unto the pure all things are pure: but unto them that are defiled... is nothing pure.'