«وَمِنْهُ حُسْنُ التَّعْلِيلِ: وَهُوَ أَنْ يُدَّعَى لِوَصْفٍ عِلَّةٌ مُنَاسِبَةٌ لَهُ بِاعْتِبَارٍ لَطِيفٍ غَيْرِ حَقِيقِيٍّ»
“Ḥusn al-taʿlīl attributes to a quality an elegant, fitting, but nonliteral cause.”
«لَمْ يَحْكِ نَائِلَكَ السَّحَابُ وَإِنَّمَا حُمَّتْ بِهِ فَصَبِيبُهَا الرُّحَضَاءُ»
“The cloud did not imitate your generosity; it caught a fever from it, and its rainfall is perspiration.”
Rain has natural causes. The poet invents an artistic explanation linked to the patron's generosity. That fitting but non-factual cause is the rhetorical figure.