I add: in this particular recension he explicitly affirms that he met Abū Saʿīd, and the wording is in harmony with all the earlier chains; this safeguards us against the possibility of his confusion or of narrating it as mursal (disconnected).
However, ʿAbd al-Ḥamīd transmitted it from Shahr, who said: “I heard Abū Saʿīd al-Khudrī—when mention was made before him of performing prayer at (Mount) Ṭūr—whereupon he said: The Messenger of Allah ﷺ said, ‘It is not fitting that mounts be readied for a journey to any mosque where prayer is sought other than the Sacred Mosque…,’” and so on. Aḥmad recorded it (3/64), and ʿUmar ibn Shabbah cited it in his work Akhbār al-Madīnah, as reproduced in al-Ṣārim al-Munkī (241).
Thus ʿAbd al-Ḥamīd—namely Ibn Bahrām—reports from Shahr a specification of the element from which the exception is made, a phrase absent from every other route of the ḥadīth, past or forthcoming, namely: “to a mosque where prayer is sought.” With this he opposes al-Layth, and although both men have been subject to criticism, ʿAbd al-Ḥamīd’s standing is better, particularly in what he narrates from Shahr. Al-Taqrīb describes him as: “He is truthful (ṣadūq).”
If he really preserved this addition from Shahr, it would mean that Shahr reported the ḥadīth according to the sense he himself understood—an interpretation that is not unanimously accepted. The more likely scenario is that it slipped in because of his weak memory and was uttered inadvertently rather than deliberately; whoever surveys his narrations finds many such extra clauses that were never related by the reliable masters. In either case, this addition cannot be relied upon, for it clashes with the versions transmitted by trustworthy narrators and is unique to Shahr alone.