As for the majority of scholars, they hold that one must fulfill every vowed act of obedience. This is based on what is recorded in Ṣaḥīḥ al-Bukhārī (1) from ʿĀʾishah, who related that the Prophet ﷺ said: “Whoever vows to obey Allah must obey Him, and whoever vows to disobey Allah must not disobey Him.” (2)
⦗120⦘ Travelling to the two mosques is an act of obedience; hence, a vow to do so must be honored. By contrast, no scholar has deemed it obligatory to travel to any site other than the three mosques when such travel is vowed. The jurists even state explicitly that one should not set out for Qubāʾ Mosque, because it is not one of the three—although visiting Qubāʾ is recommended for someone already in Madinah, since it does not involve tightening the saddle. The sound hadith says: “Whoever purifies himself in his house, then comes to Qubāʾ Mosque desiring only to pray in it, will receive a reward equal to that of an ʿumrah.” (6)
They also argue that travelling to visit the graves of prophets and the righteous is an innovation: none of the Companions or Successors ever did it, the Messenger of Allah ﷺ never commanded it, and none of the leading imams of the Muslims regarded it as commendable. Therefore, anyone who deems such travel an act of worship and undertakes it is in opposition