—Exalted is He—has made that by which he swore an object of oath, just as Allah, Exalted is He, is made an object of oath. In doing so, he has made the person or thing by which he swore a partner alongside Allah in being sworn by, and this is graver still. Thus, he has made him an associator through an associationism other than that associationism by which one becomes a disbeliever in Allah, Exalted is He, and leaves Islam.”
What he means—and Allah knows best—is that this is verbal associationism, not creedal associationism. The former is prohibited as a means of blocking the avenues that lead to evil, whereas the latter is forbidden in and of itself. This is sound and forceful reasoning. However, an exception should be made for one who swears by a saint, for if he breaks such an oath, he fears that he will be afflicted by a calamity; yet he does not fear the like of this when he falsely swears by Allah. Indeed, some ignorant people who have not yet understood the true nature of Allah’s oneness, when they deny a right owed to someone and are asked to swear by Allah, will do so despite knowing that they are lying in their oath. But when they are asked to swear by a particular saint, they refuse and admit what they owe. Almighty Allah has spoken the truth: “Most of them do not believe in Allah without associating others with Him.” (1)
2043 — “All of you will enter Paradise except one who flees from Allah as a camel runs away from its owners.”
Al-Ḥākim recorded it in al-Mustadrak (4/247), as did Aḥmad (5/258), through the route of Saʿīd ibn Abī Hilāl, from ʿAlī ibn Khālid, who said: “Abū Umāmah al-Bāhilī passed by Khālid ibn Yazīd ibn Muʿāwiyah, who asked him, ‘What was the most reassuring statement you heard from the Messenger of Allah, peace and blessings be upon him?’ He replied: ‘I heard the Messenger of Allah, peace and blessings be upon him, say,’” and then quoted it.
Al-Ḥākim cited it as corroborating evidence for the forthcoming hadith of Abū Hurayrah. Al-Dhahabī made no comment on it. Al-Haythamī said in Majmaʿ al-Zawāʾid (10/71): “Aḥmad narrated it, and its transmitters are those accepted in the authentic collections, apart from ʿAlī ibn Khālid, who is trustworthy.”
I say: However, Saʿīd ibn Abī Hilāl suffered deterioration of memory.