Whiles it remained, was it not thine own
Before it was sold, it was his own proper estate; he had the sole propriety in it, and could have kept it, or disposed of it as he pleased: he was not obliged to sell it, he might have kept it as his own property; for selling of possessions at this time was a voluntary thing; it was what no man was forced to; it was a pure act of liberality, and what was not enjoined by the apostles; every man was left to his liberty.
And after it was sold, was it not in thine own power?
that is, the price for which it was sold: before he had declared that he sold it, in order to give the whole of it to the church, had brought it to the apostles as the whole; it was in his own power to dispose of, as he pleased, whether to give the whole, or a part of it, or it. He might have kept it all if he had thought fit, or have given what portion he pleased.
Why hast thou conceived this thing in thine heart?
for though Satan had an hand in it, and greatly solicited him to it, and spirited him up to do it, yet in conjunction with his own heart; and perhaps it began there, which Satan helped forward. It was not so of Satan as to excuse the wickedness of his heart. It was owing partly to the sin of covetousness, which reigned in him, and partly to a desire of vain glory, and being thought a very religious man, that he acted such a part, and was so notoriously guilty of lying and hypocrisy.
Thou hast not lied unto men, but unto God;
that is, not to men only, for he had lied to the apostles; but to God also, to the Holy Ghost, who is truly and properly God, of which this passage is a full proof; and it was owing to his omniscience, which is a peculiar attribute of deity, that this wicked man, and this fraud of his, were discovered.