«إِذَا ثَقُلَ رُدْنِي خَفَّ عَلَيَّ أَنْ أَكْفُلَ ابْنِي»
If my sleeve grows heavy, it will become easy for me to support my son.
Rudn denotes the sleeve. Money carried within it makes the sleeve heavy (thaqula), while the duty of support becomes light (khaffa). The opposites form a clear antithesis.
Abū Zayd presents poverty as the obstacle preventing care for his alleged son. The literary logic is clear, even though the claim’s factual foundation still remains unverified.