Jamieson, Fausset and Brown on Nahum 1:15

15. This verse is joined in the Hebrew text to the second chapter. It is nearly the same as Is 52:7, referring to the similar deliverance from Babylon.

him that bringeth good tidings--announcing the overthrow of Sennacherib and deliverance of Jerusalem. The "mountains" are those round Jerusalem, on which Sennacherib's host had so lately encamped, preventing Judah from keeping her "feasts," but on which messengers now speed to Jerusalem, publishing his overthrow with a loud voice where lately they durst not have opened their mouths. A type of the far more glorious spiritual deliverance of God's people from Satan by Messiah, heralded by ministers of the Gospel (Ro 10:15).

perform thy vows--which thou didst promise if God would deliver thee from the Assyrian.

the wicked--literally, "Belial"; the same as the "counsellor of Belial" (Na 1:11, Margin); namely, Sennacherib.