Hast sent letters. These may have been sent by the messengers named in v. 3 when they returned from Babylon. When the messages reached Jerusalem, Jeremiah was apprised of them. As a result he sent a reply message severely rebuking Shemaiah.
Zephaniah. Inasmuch as he was “the second priest” (Jer. 52:24; cf. 2 Kings 25:18), it was hoped that his authority and influence would prevent Jeremiah from prophesying, and that he would be punished as a deceiver. Zephaniah acted for King Zedekiah in a sort of temporizing fashion (see Jer. 21:1; 37:3). Later on, when Nebuzaradan, the Babylonian “captain of the guard,” captured Jerusalem, Zephaniah was taken prisoner and executed (ch. 52:24-27).