He speaks to the people in the temple, and especially to the leaders who have responsibility.
He is teaching them, giving them education and explaining the meaning of what he has done. He makes the meaning of his act clear from the Scriptures. He is not a rebel against the temple and the authority of the scribes and priests, but he is the Teacher who explains God’s Word and applies it.
17 Et il enseignait et disait: N'est-il pas écrit: Ma maison sera appelée une maison de prière pour toutes les nations? Mais vous, vous en avez fait une caverne de voleurs.