How authentic is the saying, "Were it not for Ali, Umar would have perished," and is it authentically reported that Umar ibn al-Khattab said it?

The saying, "Had it not been for Abu al-Hasan, Umar would have perished," is not attributed to Umar ibn al-Khattab, may Allah be pleased with him, with certainty and verification. Rather, it is mentioned as being attributed to him in some books, such as "Fath al-Bab fi al-Kuna wa al-Alqab" and "Al-Isti'ab," without a chain of narration (isnad). As for what was narrated with a weak chain from Mu'ammal ibn Isma'il, that Umar used to seek refuge with Allah from a difficult problem for which there was no Abu al-Hasan, its weakness is apparent due to the weakness of Mu'ammal and the discontinuity of the chain. The correct version of this saying is that it was said concerning Mu'adh ibn Jabal, may Allah be pleased with him: "Had it not been for Mu'adh, Umar would have perished." This was narrated by Abd al-Razzaq and others with a reliable chain, and although Ibn Hazm deemed it weak, some verifiers believe that the anonymity of the shaykhs in the chain does not harm it due to their multiplicity.