How does one know that God was in the inner temple?

This text is from a transcript of a talk by David Gooding, entitled ‘God’s Glorious Plan for Creation’ (2007).

How does one know God was in the inner temple if people were not allowed in? Was it just a presence of God? Well in one sense, yes, it was just a presence of God. If you had gone into the holiest of all, you wouldn't have seen God anyway. The presence of God in the tabernacle that Moses built, which the Jews used while they were travelling through the wilderness and for some centuries afterwards, or in the temple at Jerusalem, was symbolized by the cloud of glory that filled the temple. But no one ever saw God in it. No one can see God. So they knew about God's presence in the temple because of the glory of his presence in the Holy Place. And then they knew it, of course, because the Scripture says so.

Similarly in the New Testament, Christ says, 'For where two or three are gathered in my name, there am I among them' (Matthew 18:20). You say, 'How do you know he is?' Well we don't see him, but (1) we know he's there, because he's promised to be there and (2) when he speaks his word through Scripture, we know his voice. We sense he's speaking to us.