Albert Barnes Commentary Jeremiah 7:4

"Trust ye not in lying words, saying, The temple of Jehovah, the temple of Jehovah, the temple of Jehovah, are these." — Jeremiah 7:4 (ASV)

The temple of the Lord - Thrice repeated, to emphasize the rejection of the cry constantly on the lips of the false prophets. In their view, the maintenance of the temple service was a charm sufficient to avert all evil.

These - The buildings of the temple, to which Jeremiah is supposed to point. The Jews put their trust in the material buildings.