Taʾkid al-dhamm bima yushbih al-madh reverses the procedure. The speaker seems about to introduce a redeeming merit, but the alleged exception turns out to be another fault. This strengthens censure.
«فُلَانٌ لَا خَيْرَ فِيهِ إِلَّا أَنَّهُ يَتَصَدَّقُ بِمَا يَسْرِقُ»
There is no good in that person, except that he gives charity from what he steals.
“Charity” sounds commendable, but its illicit source makes the apparent praise into further blame.