If someone were to argue, “All the transmitters I have left out are trustworthy,” the question of endorsing an unidentified narrator arises, and the majority (1) rule that such an endorsement is not accepted until the person is actually named (2).
However, Ibn al-Ṣalāḥ remarks here (3): “When an omission occurs in a book (4) whose author has bound himself to record only sound reports—such as that of al-Bukhārī—then whatever he presents therein (5) with decisive wording, jazm, shows (6) that, in his assessment, its chain of transmission is firmly established (7) and that the names were omitted for some specific purpose. As for anything he introduces without such decisive wording, it remains open to objection (8).”
I have set out examples of this (9) in my work al-Nukat ʿalā Ibn al-Ṣalāḥ (10, 11).
(1) MS Ṭ reads: “fa-l-jumhur” (“whereas the majority”).
(2) MS M has yusammiya (“that he name”); the reading adopted here follows MSS B, W, Ṭ, and K. See: al-Kifayah by al-Khatib, p. 92; and al-Iraqi, Sharh al-Tabsirah wa-l-Tadhkirah, 1/346.
(3) The word huna (“here”) is absent from MSS D and H.
(4) MS K reads min (“from”).
(5) MS K has bihi (“with it”); a copy with a marginal note reads fihi (“in it”).
(6) MS Y reads dalil (“proof”); a copy with a marginal note has dalla (“indicated”).
(7) MS Ṭ gives “ʿindahu isnaduhu” (“its chain is with him”) with the words transposed.
(8) See: Ibn al-Salah, Muqaddimah, p. 24.
(9) The word amthilata (“examples”) is not found in MS H.
(10) The phrase fi-l-nukat (“in al-Nukat”) is missing from MS A.
(11) In al-Nukat, 1/325, the author (may Allah have mercy on him) explains the reasons for this practice: “Either because he did not obtain it through direct audition but only by way of discussion or ijazah; or because he had already extracted a report that fulfilled its purpose and thus dispensed with citing this muʿallaq in full; or for some other reason. Some such reports fall short of his own criteria, even if others declare them sahih or hasan, and some are weak solely on account of a break in the chain.” In the margin of MS D, in the author’s own handwriting, is the note: “Then it reached me likewise.” In the margin of MS W, also in his hand: “Then it reached me; I reviewed the reading. Written by: Ibn Hajar.”