In this example, Ya‘lā ibn ‘Ubayd’s report names عمرو بن دينار in place of عبد الله بن دينار.
• Reading this chain alone does not make the error obvious.
• Comparing it with the reports of al-Thawrī’s other students reveals the difference.
• The defect in this particular chain concerns the narrator’s name, not the wording of the sentence about buying and selling.