Albert Barnes Commentary Isaiah 6:4

"And the foundations of the thresholds shook at the voice of him that cried, and the house was filled with smoke." — Isaiah 6:4 (ASV)

And the posts of the door - Margin, ‘Thresholds.’ There is some difficulty in the Hebrew here, but the meaning of the expression is sufficiently apparent. It means that there was a tremor, or concussion, as if by awe, or by the sound attending the cry. It is evidently a poetic expression.

The house - The temple.

Was filled with smoke - There is here, doubtless, a reference to “the cloud” that is so often mentioned in the Old Testament as the visible symbol of the Divinity; see the note at Isaiah 4:5. A similar appearance is recorded when Solomon dedicated the temple; 1 Kings 8:10; 2 Chronicles 5:13; Ezekiel 10:4.