Then said he unto me, Son of man, dig now in the wall: and when I had digged in the wall, behold a door.

Wesley's Notes

8:8 A door - A private door, by which the priests entered into the chamber of their imagery, to perform idolatrous worship to their images.

Jamieson-Fausset-Brown Bible Commentary

8. dig-for it had been blocked up during Josiah's reformation. Or rather, the vision is not of an actual scene, but an ideal pictorial representation of the Egyptian idolatries into which the covenant-people had relapsed, practising them in secret places where they shrank from the light of day [Fairbairn], (Joh 3:20). But compare, as to the literal introduction of idolatries into the temple, Eze 5:11; Jer 7:30; 32:34.

Matthew Henry's Concise Commentary

8:7-12 A secret place was, as it were, opened, where the prophet saw creatures painted on the walls, and a number of the elders of Israel worshipped before them. No superiority in worldly matters will preserve men from lust, or idolatries, when they are left to their own deceitful hearts; and those who are soon wearied in the service of God, often grudge no toil nor expense when following their superstitions. When hypocrites screen themselves behind the wall of an outward profession, there is some hole or other left in the wall, something that betrays them to those who look diligently. There is a great deal of secret wickedness in the world. They think themselves out of God's sight. But those are ripe indeed for ruin, who lay the blame of their sins upon the Lord.