‘While it remained, did it not remain your own? and after it was sold, was it not in your power? How is it that you have conceived this thing in your heart? You have not lied to men, but to God.'
Peter made the position quite clear. What he had done had not been necessary. It was not as though the Apostles had demanded that he give everything that he had. That was true of various sectaries around, such as the Qumran community, who demanded such sacrifices, but it had not been true here. He had been free to do what he chose. The money had been his to do what he wanted with.
Indeed it should be noted here that the general situation in Judaism was that only a proportion be given. When Zacchaeus expressed his love for Jesus he declared that he would give a half of his goods, as well as restitution (Luke 19:8), and this would be seen as extremely generous. The Mishnah declared that only a proportion of goods was to be offered to the Temple and that to give the whole was not valid. Elsewhere acts of charity were limited to one fifth of a man's means. On the other hand Rabbi Johanan was deeply respected for selling all his possessions for the sake of studying the Torah. Thus those who gave all, while following Jesus to the letter (Luke 12:33), were very much going beyond the norm.
And yet in the face of the generosity of God in giving him free choice Ananias had conceived in his heart to lie to God. For that was his crime. He had chosen darkness rather than light because his deeds were evil. He did not want to walk in the light. And it had been a planned action, not a sudden impulse.