80 In exposition of this hadith...

80 In exposition of this hadith, Ibn Hajar says: “In al-Zubayr’s tenacity to this hadith for its indicating his paucity in narrating the hadith, is found the best evidence to show that falsity means to tell of something in a way opposite to its truth, whether deliberately or mistakenly. And though that who errs is not sinful as unanimously agreed by Muslim scholars, but al-Zubayr feared that prolification (in narration) might lead him to commit a mistake unconsciously.

Because though he has not sinned through erring, but he may sin by prolification as it entails mistaking, and it will be regarded an error on his part, – without his sensing it to be so – the method adopted to be sure of his reporting, the fact rendering him to be a cause for adopting rules that were never revealed by the Law-Giver. Thus, whoever fearing…