«وَمَا ضَنَّ إِلَّا غَبِينٌ، وَلَا غَبَنَ إِلَّا ضَنِينٌ»
Only one who loses by it behaves miserly, and one who wrongs another by deprivation is miserly.
Ḍann means withholding or stinginess; ghabīn is someone who suffers a loss in a bargain; ghaban concerns unfair deprivation or loss. The two clauses exchange the roles of the words to create a compact verbal reversal.
The effect resembles inversion and counterturn: the ear hears related sounds again, while the thought returns from avarice to its harmful consequences.
The same section criticizes khazn / qabḍ—hoarding and withholding. The wordplay about stinginess thus moves naturally into the practical consequences of refusing help.