Why hath Satan filled thine heart? — The narrative is obviously intended to leave the impression that St. Peter’s knowledge of the fact came from a supernatural insight. He had that prophetic gift which gave him insight into the hearts of men, and through this outward show of generous devotion he read the baseness and the lie. And that evil he traced to its fountain-head. Like the sin of Judas (John 13:2; John 13:27), it had in it a malignant subtlety of evil, which implied the perversion of conscience and will just at the moment when they seemed to be, and, it may be, actually were, on the point of attaining a higher perfection than before. The question “why” implies that resistance to the temptation had been possible. Had he resisted the Tempter, he would have fled from him (James 4:7).
To lie to the Holy Ghost. — The words admit of two tenable interpretations. Ananias may be said to “have lied unto the Holy Ghost,” either (1) as lying against Him who dwelt in the Apostles whom he was seeking to deceive; or (2) as against Him who was the Searcher of the secrets of all hearts, his own included, and who was “grieved” (Ephesians 4:31) by this resistance in one who had been called to a higher life. The apparent parallelism of the clause in Acts 5:4 is in favour of (1); but there is in the Greek a distinction, obviously made deliberately, between the structure of the verb in the two sentences. Here it is used with the accusative of the direct object, so that the meaning is “to cheat or deceive the Holy Spirit;” there with the dative, “to speak a lie, not to men, but to God;” and this gives a sense which is at least compatible with (2). The special intensity of the sin consisted in its being against the light and knowledge with which the human spirit had been illumined by the divine. The circumstance that it was also an attempt to deceive those in whom that Spirit dwelt in the fulness of its power comes in afterwards as a secondary aggravation.