«فَنَهَضْتُ فِيمَا أَمَرَ لِأَدْرَأَ عَنْهُ الْغَمْرَ»
I rose to do what he asked, hoping to spare him discomfort.
Al-Ḥārith acts from hospitality, not suspicion. Fa-nahaḍtu is first-person past tense, while the purposive li- in li-adraʾa indicates his intention to avert discomfort. His good-faith action supplies the opening Abū Zayd requires.