and see "al-Ṣaḥīḥah" (1646 and 1733).

"Indeed, Islam has a fervor, and every fervor has a period of slackening. If its companion is moderate and approaches [the right path], then hope for him; but if he is pointed at with fingers, then do not hope for him." Narrated by al-Ṭaḥāwī in "Mushkil al-Āthār" (2/89) and Tamām (163/1) from Bakkār ibn Qutaybah: Safwān ibn ʿĪsá narrated to us, Muḥammad ibn ʿAjlān narrated to us from al-Qaʿqāʿ ibn Ḥakīm from Abū Ṣāliḥ from Abū Hurayrah, raised [to the Prophet]. I say: This isnād is good, all its men are trustworthy, with the well-known disagreement regarding Ibn ʿAjlān. And Bakkār ibn Qutaybah is among the shaykhs of Ibn Khuzaymah, declared trustworthy by Ibn Ḥibbān (8/152), and he has a good biography in "Tārīkh Ibn ʿAsākir" (3/411-415), and he was a judge of the Ḥanafī school. And Safwān ibn ʿĪsá is trustworthy, among the men of Muslim. Ḥātim ibn Ismāʿīl corroborated him from Muḥammad ibn ʿAjlān with it. It was also recorded by al-Tirmidhī (2455) and Ibn Ḥibbān (652). Al-Tirmidhī said: "ḥasan ṣaḥīḥ gharīb." The ḥadīth has a corroborating narration from Ibn Isḥāq: Abū al-Zubayr al-Makkī narrated to me from Abū al-ʿAbbās, the client of Banī al-Dayl, from ʿAbd Allāh ibn ʿAmr who said: Men from the companions of the Messenger of Allāh (ṣallá Allāhu ʿalayhi wa-sallam) were mentioned to him, who exerted themselves intensely in worship. The Messenger of Allāh (ṣallá Allāhu ʿalayhi wa-sallam) said: "That is the zeal of Islam and its fervor, and every zeal has a fervor, and every fervor has a period of slackening, so whoever..