And a man lame from birth was being carried, whom they laid daily at the gate of the temple that is called the Beautiful Gate to ask alms of those entering the temple.
Acts 3:2

This lame man probably came to the Temple for the daily sacrifices because he knew there would be crowds of pious people passing in and out. He had to be there before the main crowds or he would miss the best donors. Since he had just arrived, Peter and John were probably also there early to get good places for the service.