Albert Barnes on Luke 1:22

Had seen a vision. The word vision means sight, appearance, or spectre, and is commonly applied to spirits, or to beings from another world. When he came out of the temple, it is probable that they suspected that something of this nature had detained him there, and that, on inquiry of him, he signified by a nod that this was the case. He was unable to speak, and they had no way of "perceiving" it but by such a sign. On the word vision, Isa 1:1.

For he beckoned unto them. That is, by beckoning unto them, or by a sign, he informed them of what he had seen.