Hawzah News Agency - In an article written by Shia source of emulation Grand Ayatollah Nasser Makarem Shirazi has answered the question of why the Qibla changed from Al-Aqsa Mosque to Ka'ba, which you can read below:

Brief answer:

A few months after the migration, the Jews were blaming the Muslims for praying towards Al-Aqsa Mosque; after a while, Prophet Muhammad (PBUH) was engaged in the noon prayer in the Bani Salem Mosque when Gabriel came and took the Prophet's (PBUH) arm and turned him towards the Kaaba, and the order to change the Qibla was issued. The Jews were upset by this incident and again made excuses. God gave a decisive answer that the east and west of the world belong to God and no place has inherent dignity without His grace.