THE CHAPTER OF THE NEZRITES · 24 – THE STATUS OF SOMEONE WHO INTENDS TO PRAY IN JERUSALEM (BAYT al-Maqdis)
Jabir ibn Abdullah (may Allah be pleased with him) narrated:
On the day of the conquest of Mecca, a man stood up and said, "O Messenger of Allah! If Allah makes it possible for you to conquer Mecca, I had vowed to pray two rak'ahs at al-Aqsa Mosque for Allah." The Messenger of Allah (peace and blessings be upon him) commanded, “Pray here.” The man repeated his vow. The Messenger of Allah (peace and blessings be upon him) commanded, “Pray here.” Then the man repeated his vow again. This time, the Messenger of Allah (peace and blessings be upon him) said, "Then you know best."
EXPLANATION
The statement "Then you know best" in the final sentence of this hadith means: If you are able to go to Jerusalem and pray at al-Aqsa Mosque, then go and do so; if not, pray here. According to Imam al-Shafi'i, someone who vows to perform Hajj on foot, if he has the ability, performs it on foot; if he does not have the ability, he performs it by riding an animal, and slaughters a sacrifice because he did not fulfill his vow of performing Hajj on foot.
From 'Umar ibn 'Abd ar-Rahman ibn Awf, may Allah be pleased with him, from among some of the companions, the following report was narrated; this narration contains the statement: "I swear by Allah who has sent me as a Prophet, that performing prayers in this place is sufficient for the prayer you perform in Bayt al-Maqdis." This is an addition.
EXPLANATION: Whoever intends to fulfill a vow by praying in a mosque can do so, even if he cannot go elsewhere.