David is showing his conversion here and how he had understood that this metaphor stretches a lot further than just our physical life.
He is telling us here with just that little word selah. . . Usually commentators think it is a musical interlude where you have time to think about the lyrics that had just been spoken of. And you could say, Oh, that's what David meant.
He is actually preaching the gospel here in his own way. He is saying there is more to this concept of dwelling in a tabernacle, dwelling in a tent. This goes on forever. What does that mean?
And then he adds the idea I will trust in the shelter of Your wings. What has he just brought in? Our heart, faith. I will trust in the shelter of Your wings, I will trust that You are there, that You are enclosing me like a hen will enclose her chicks to protect them.