«فَلَمَّا رَأَى أَبُو زَيْدٍ امْتِلَاءَ كِيسِهِ وَإِجْلَاءَ بُؤْسِهِ»
When Abū Zayd saw that his purse was full and his hardship relieved.
Kīs is a purse or bag; buʾs indicates hardship. The near-rhyme of imtilāʾ / ijlāʾ accompanies the balanced ideas of filling a purse and removing distress.
The order of events is deliberate. Two poorly dressed travellers have now benefited from hospitality; only then does Abū Zayd request permission to go elsewhere. The outcome will show what that request means.