and Abu Dawud, al-Nasa’i, and others do likewise.
When they move down to citing the hadiths of the weak transmitters who belong to the fourth tier, they are selective: they choose only certain reports and do not record them exhaustively, each compiler acting according to his own view and personal judgment.
As for the fifth tier—those unanimously set aside and abandoned, whether for poor comprehension and faulty accuracy or because they are suspected of dishonesty—Aḥmad and al-Nasa’i seldom narrate from them.
Abu ‘Isa (al-Tirmidhi) will on occasion include one of their reports and clarify its status according to his own ijtihad, but such cases are rare.
Ibn Majah records a small number of their hadiths and, Allah knows best, offers no clarification.
Abu Dawud almost never transmits from them; if he does, he usually makes their weakness explicit (1).
With regard to the sixth tier—namely the extremist Rafiḍis and the Jahmis who actively propagate their views, along with the habitual liars and fabricators and the disgraced narrators who have been cast aside, such as ʿUmar ibn al-Ṣubḥ, Muhammad al-Maṣlūb, Nūḥ ibn Abī Maryam, Aḥmad al-Juwaybarī, and Abū Hudhayfa al-Bukhārī—there is not a single letter of theirs in the recognised collections. The only exception is ʿUmar, for Ibn Majah recorded one hadith from him (2), and in this he erred.
Likewise, Ibn Majah recorded a single hadith from al-Waqidī.
(1) Al-Hafiz Ibn Hajar cites al-Nawawi as saying: “In Sunan Abi Dawud there are narrations whose weakness is patently clear, yet he does not flag them as such, even though their weakness is unanimously acknowledged; his statement therefore requires interpretation.” Ibn Hajar then adds: “The sound rule is that any report we find in his Sunan which he leaves without comment and which none of the reliable authorities has declared sahih (sound) or hasan (fair), or in whose chain a qualified scholar detects a cause of weakness with no supporting evidence, must be judged weak, and Abu Dawud’s silence carries no weight.” I say: this is the correct assessment, yet al-Nawawi contradicts it on many occasions in Sharh al-Muhadhdhab and other works, where he adduces numerous hadiths solely because Abu Dawud remained silent about them; do not be misled by that. The passage is quoted from him by al-Sanʿani in Tawdih al-Afkar, 1/199. See also Mahmud Muhammad Khattab, Al-Manhal al-ʿAdhb al-Mawrud fima Sakata ʿalayhi Abu Dawud, 1/18.
(2) Sunan Abi Dawud, no. 2768, Book of Jihad, chapter “The virtue of ribat in the path of Allah,” through the chain: Muhammad b. Ismail b. Samurah – Muhammad b. Yaʿla al-Salami – ʿUmar b. Subh – ʿAbd al-Rahman b. ʿAmr – Makʿhul – Ubayy b. Kab. The Prophet ﷺ said: “Guarding the frontier for one day in the path of Allah, protecting the vulnerable flank of the Muslims and seeking the divine reward, outside the month of Ramadan, is more meritorious than worship for one hundred years.”