Acts 7:53

“You who received the law as it was ordained by angels, and did not keep it.”

But, he is saying, it is not really surprising that they had rejected the Righteous One, for these are the ones who had been privileged to receive the Law as ordained by angels, and still had not kept it. The two ideas went together. The one was preparing for the other, and their failure to do the one resulted in the other.

‘And did not keep it.' Thus from this all should know who really sought to change the Law of Moses. In actual fact the Pharisees to a man would have admitted to each other that they did not keep the Law fully. It was not the fact of it that they would resent. It was the implication that they were not Law-keepers. Why they struggled to keep it with might and main. But as Jesus had pointed out, that was not God's Law, it was the Law as determined by man, the Law ‘made by hands'.

The idea that the Law was ordained by and mediated by angels was orthodox Jewish belief, based on their view that the transcendent God could not deal with man directly. This was a basic contradiction to how they actually, (as opposed to theologically), viewed the Temple. Actually they saw the Temple and its ordinances as binding God by their rituals, even though theoretically they did see Him as transcendent. For the idea of angel mediation compare Galatians 3:19; Hebrews 2:2.

Luke probably here expects us to relate this statement to Stephen's face being like that of an angel when he began his defence (Acts 6:15). They had not listened to angel's then, they did not listen to God's messenger now.