Abū Zayd leaves swiftly, and his son also heads away. The narrator and his fellow travellers remain at camp, expecting an early return because the stated errand was short.
«بِدَارًا بِدَارًا»
Quickly, quickly!
Bidār conveys haste or rushing forward. Its repetition recalls the narrator's earlier demand for a quick return. The irony is now becoming visible: the men appear to be hurrying away, not hurrying back.
The narrator has not yet received conclusive proof of deceit; the long wait is about to provide that proof.