They are all grievous revolters, walking with slanders: they are brass and iron; they are all corrupters.
Grievous revolters - literally, contumacious of the contumacious - i:e., most contumacious, the Hebrew mode of expressing a superlative. So "the strong among the mighty" - i:e., the strongest (Ezekiel 32:21). See Jeremiah 5:23; Hosea 4:16.
Walking with slanders - (Jeremiah 9:4). 'Going about for the purpose of slandering' (Maurer).
Brass ... - i:e., copper. It and 'iron' being the baser and harder metals express the debased and obdurate character of the Jews (Isaiah 48:4, "Thy neck is an iron sinew, and thy brow brass." In the coming restoration of all things and of the Jews first, God promises, "For brass I will bring gold, and for iron I will bring silver," 60:17).