1199 – Jabir (may Allah be pleased with him) related that on the Day of the Conquest a man said, “O Messenger of Allah, I have vowed that if Allah grants you victory over Mecca, I will perform a prayer in Bayt al-Maqdis (Jerusalem).” The Prophet replied, “Pray here.” The man repeated his request, and again he said, “Pray here.” When he asked a third time, the Prophet said, “Then do as you wish.” Reported by Ahmad and Abu Dawud, and al-Hakim declared it authentic.⦗1⦘

Grade of the hadith:
The hadith is ṣaḥīḥ (authentic). The compiler notes that it was narrated by Ahmad and Abu Dawud; al-Hakim judged it sound, a verdict with which al-Dhahabi concurred, and Ibn Daqiq al-ʿId also classified it as authentic.

Vocabulary:
– sha’naka is in the accusative case, meaning “attend to your own affair.”
– idhān here functions as a response of consequence: “If you refuse to pray here, then carry out what you vowed—pray in Bayt al-Maqdis.”

Points derived from the hadith:
1 – A vow that is suspended on the attainment of a desired outcome—such as, “If Allah heals my sick relative,” or, “If my missing wealth returns, then for Allah I will…”—whether the promised act is bodily worship (prayer, fasting) or financial worship (charity, manumission), becomes binding. Once the stipulated condition materializes, the person is obliged to fulfil what he pledged. One may also vow an act of obedience without attaching it to any condition, for example: “For Allah I am committed to perform such-and-such prayers or fasts.”