I heard my father say, I heard the Messenger of Allah ﷺ saying, "Faith began as something strange and will return to being strange just as it began, so blessed are the strangers on that day when people have grown corrupt. By the One in whose hand is the soul of Abu Qasim, faith will retreat between these two mosques just as a snake retreats into its hole."
حدثنا هارون بن معروف أنبأنا عبد الله بن وهب أخبرني أبو صخر قال أبو عبد الرحمن عبد الله بن أحمد وسمعته أنا من هارون أن أبا حازم حدثه
سمعت أبي يقول سمعت رسول الله ﷺ وهو يقول إن الإيمان بدأ غريبا وسيعود كما بدأ فطوبى يومئذ للغرباء إذا فسد الناس والذي نفس أبي القاسم بيده ليأرزن الإيمان بين هذين المسجدين كما تأرز الحية في جحرها
Its chain is sahih, despite the ambiguity regarding Ibn Saad bin Abu Waqqas, for his sons are all trustworthy and well known. Abu Hazim Salama bin Dinar is a thiqah, firmly reliable, from the younger generation of the Tabiin, and there was none like him in his time, so it cannot be supposed that he would narrate from an unidentified man claiming to be Ibn Saad.Abu Sakhr is Humayd bin Ziyad al-Kharrat, from Madinah, who settled in Egypt. He is thiqah, declared so by Daraqutni and Ibn Hibban, while Ahmad and Ibn Main said, "There is no harm in him." Bukhari gave his biography in al-Kabir 1/2/348 and mentioned no criticism of him.As for the statement of Abdullah bin Ahmad, "and I heard it myself from Harun," and so on, he does not mean by its apparent wording that Harun heard it from Abu Hazim, for that would not make sense. Rather, it is appended to his father's chain, following it, meaning that Harun narrated it from Ibn Wahb, from Abu Sakhr, that Abu Hazim had related it to him, and that Ahmad and his son heard it from Harun. So the pronoun in "related it to him" refers back to Abu Sakhr.The wording of the hadith is sahih and well known through the narration of Abu Hurairah and others, see al-Jami al-Saghir 1951, 1958.Ibn Athir explained it, saying, it means that in his situation he was like a lone stranger with no family present with him, due to the scarcity of Muslims at that time, and it will return to being strange as it was, meaning that Muslims will become few in the later times and will become like strangers.As for "it will surely draw together," and so on, it means that it will gather between the two mosques of Makkah and Madinah, coming together part with part.