When he came out and was unable to speak to them, they realized he had seen a vision in the temple. He kept making signs to them but remained unable to speak.
KJV
And when he came out, he could not speak unto them: and they perceived that he had seen a vision in the temple: for he beckoned unto them, and remained speechless.
ASV
And when he came out, he could not speak unto them: and they perceived that he had seen a vision in the temple: and he continued making signs unto them, and remained dumb.