‘And Cornelius said, “Four days ago, until this hour, I was keeping the ninth hour of prayer in my house, and behold, a man stood before me in bright clothing, and says, “Cornelius, your prayer is heard, and your charitable giving is had in remembrance in the sight of God. Send therefore to Joppa, and call to you Simon, who is surnamed Peter. He lodges in the house of Simon a tanner, by the sea side.”
Cornelius them explained his side of the story, how a man in bright clothing had appeared to him, and had told him that God had heard his prayers as he had sought for Him, and that God had seen the godliness and devoutness of his life, and that he was therefore to send to the house of Simon the Tanner for a man called Simon Peter.
This is the first indication that we have had that the angel was clothed in ‘bright clothing'. That explains why Cornelius had known that he was the Angel of God. Nevertheless here in front of his friends he tones the description down of the angel down to ‘a man in bright clothing'. He is a little self-conscious about what his friends might think.
Now, however, we recognise why he had seen in Peter a great prophet to whom homage should be paid. He recognised that he must clearly be greater than the Angel who was but a messenger.
Note the repetition of what had happened. It is being emphasised what a devout man Cornelius is, and that he was pleasing to God, and was the equivalent of a pleasing odour to Him (memorial). Peter and his companions are also being made aware that all this is of God, and is because of God's command, just as He had commanded concerning the unclean creatures.