A.T. Robertson Commentary Luke 1:22

"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." — Luke 1:22 (ASV)

Perceived (επεγνωσαν). Second aorist indicative. Clearly knew because he was not able to pronounce the benediction from the steps (Numbers 6:24–26).

Continued making signs (ην διανευων). Periphrastic imperfect again. He nodded and beckoned back and forth (δια, between). Further proof of a vision that caused his dumbness.