I say: This is a good chain of transmission; all its narrators are trustworthy. Baqiyyah is only feared on account of his ambiguous mode of transmission, because he practised concealment in transmission; but he explicitly stated that he heard it, and so we are safe from his concealment.
447 — “Poetry is like speech: its good is like good speech, and its bad is like bad speech.”
Al-Bukhārī narrated it in al-Adab al-Mufrad (125), as did al-Dāraquṭnī (490), through Ismāʿīl ibn ʿAyyāsh, from ʿAbd al-Raḥmān ibn Ziyād ibn Anʿum, from ʿAbd al-Raḥmān ibn Rāfiʿ, from ʿAbd Allāh ibn ʿAmr, attributed to the Prophet, peace and blessings be upon him.
I say: This chain consists successively of weak narrators—Ismāʿīl ibn ʿAyyāsh and all those above him. For this reason, al-Ḥāfiẓ decisively judged it weak, saying in al-Fatḥ (10/443), after attributing it to al-Adab al-Mufrad: “Its chain is weak. Al-Ṭabarānī also narrated it in al-Awsaṭ and said: ‘It is not narrated from the Prophet, peace and blessings be upon him, except through this chain of transmission.’”
As for al-Haythamī’s statement (8/122), after attributing it to al-Awsaṭ, “Its chain is good,” it is not good.
Yet it has supporting reports that raise it to the rank of good. Among them is the report from ʿĀʾishah, who said: “The Messenger of Allah, peace and blessings be upon him, was asked about poetry, and he said: ‘It is speech: its good is good, and its bad is bad.’” Al-Haythamī said: “Abū Yaʿlā narrated it, and its chain includes ʿAbd al-Raḥmān ibn Thābit ibn Thawbān, whom Duḥaym and a group declared trustworthy, while Ibn Maʿīn and others declared him weak. The remaining narrators are narrators of the Ṣaḥīḥ collections.”
I say: If it has no defect other than this Ibn Thawbān, then its chain is good, for Ibn Thawbān is truthful but makes errors, as stated in al-Taqrīb.