Isaiah 9:18

Burneth as the fire. This is a striking description of the final effects of iniquity. Sin kills, but it does not heal. Wickedness burns and creates ashes and desolation, but it does not repair or build. Briers and thorns, fit only for destruction, symbolize the iniquity that prevailed among the people (see chs. 5:6; 7:23-25; 10:17; 27:4; 32:13). When the land became covered with a rank growth of brambles and briers that crowded out the good trees of the forest, then wickedness would break forth as a fire to consume itself.

Sin would be punished; it would, in fact, bring about its own destruction (see Isa. 33:11, 12; Jer. 21:14; Joel 1:19, 20; Heb. 6:8). Thus the land would be left clear, ready for a new growth of wholesome verdure (see 2 Peter 3:10-13).