“Thus says the LORD, “Though they are at full strength and many, they will be cut down and pass away. Though I have afflicted you, I will afflict you no more.” (Nahum 1:12)
Whenever we read scripture we must be aware of who is speaking, who they are speaking to, and who is being spoken about. Pay close attention to who “they, them, you, we” and such pronouns are referring to. It is not always clear on the first read-through, so take your time. Here we have Nahum quoting God, who is speaking.
The switch at the beginning of the verse and again in mid-verse is very important.
Verse 10 is speaking to God’s people about God’s enemies.
Verse 11 speaks to God’s enemies about God’s enemies.
Verse 12 begins speaking to God’s people about God’s enemies, and ends speaking to God’s people about God’s people.
“I will afflict you (My people) no more”. When God punishes his wayward people to correct them, the punishment has an end. When he judges His enemies, there is no such promise of an end to the affliction.
John Calvin begins the translation of this verse “though they be quiet and also strong” noting that Ninevah had promised themselves tranquility, safety from attack, because they were well defended by massive infrastructure and by a huge armed force. The charge was that they thought they could live a quiet life due to their strength. They had a big army, a big city, with big defenses, in a big territory, with a big economy. “Peace in our time!” Though it is not stated here it is logical to suppose they were proud of their in enlightened culture and the strength of their gods and religion. This is speculation but the strong and secure can always find “reasons” to praise themselves for their superior positions. Proud people will always praise themselves for their own cleverness. And God laughs!