WordMeaningLiterary roleصَبَابَةArdent longingExcess of desireصُبَابَةA small remainderEnough rather than excess
The same consonants, with different vowels, create distinct meanings. Recognizing the wordplay requires attention to letters, vocalization, and context.
The effect is structural as well as decorative: the movement from obsessive desire to sufficient provision makes the poem's lesson memorable.