God will judge the guilty.
Nahum 1:3 provides the only occurrence of the expression “slow to anger” that is not immediately followed by “abounding in steadfast loveThe steadfast love (hesed) of God is the assurance of God's loving kindness, faithfulness, and mercy. This assurance rings throughout the Old Testament, and is affirmed more than 120 times in the Psalms. In some hymns of praise the response of the people was likely... More.” “Slow to anger” also occurs in Exodus 34:6; Numbers 14:18; NehemiahThe governor of Jerusalem who rebuilt the city walls after the exile More 9:17; Psalms 86:15; 103:8; 145:8; and JonahA rebellious prophet who fled from the Lord's command, only to be delivered by a big and fish and bring about the repentance of Nineveh More 4:2. In Exodus 34 and Numbers 14 the declaration that the guilty will not be cleared does occur in subsequent clauses, as it does in Nahum 1:3, but, unlike Nahum 1:3, “abounding in steadfast love” occurs immediately after “slow to anger.” It appears that in 1:2-8 Nahum works with stock expressions, but modifies them slightly to fit his core message. “Abounding in steadfast love” is not the core theme that Nahum addresses, although there is comfort for JudahJudah was the name of Jacob's fourth son and one of the 12 tribes. More (1:12, 15). Nahum focuses on the very specific removal of Assyrian oppression. Whether or not more was previously said to Judah or would need to be said later, it is left for other canonical texts to say it.