Ḥusn al-intihāʾ requires the final line or clause to suit the purpose of the whole composition, avoid introducing an awkward new theme and leave a sense of completion. A prayer for the praised person can serve this aim in a panegyric.
بَقِيتَ بَقَاءَ الدَّهْرِ يَا كَهْفَ أَهْلِهِ
May you endure as long as time, O refuge of its people.
The prayer for continued life reinforces the addressee's characterization as a refuge, making the ending appropriate to its occasion. Pleasant rhythm or rhyme is insufficient by itself: the last words should complete the persuasive and emotional effect of the work.