John Trapp on Jeremiah 9:8

Ver. 8. Their tongue is as an arrow ſhot out] It is both a bow, ver. 3. and a ſhaft, and that a ſlaughtering ſhaft, Jun. Piſc. as ſome coppies have it here; culter jugulans, a murthering-knife, ſome render it. So Pſal. 42.10. As with a murdering weapon in my bones, mine enemies reproach me. Reckon thou, ſaith one, Sennacherib and Rabſhakeh among the firſt, and chiefeſt Kill-Chriſts, becauſe ever an honeſt mind is more afflicted with words then with blows.

It ſpeaketh deceit] See Pſal. 52.2. with the Notes.

One ſpeaketh peaceably — but in his heart he layeth his wait] Such a one was the tyrant Tiberius and our Richard 3. who would uſe moſt complements and ſhew greateſt ſigns of love and curteſie to him in the morning,Dan hiſt. 249. whoſe throat he had taken order to be cut that evening.