Is it permissible for me to combine prayers—by advancing the Asr prayer before its due time—in the Grand Mosque (Masjid al-Haram) in Makkah, due to the virtue of praying there, knowing that I reside in Jeddah and the distance between the two cities is not considered a distance for shortening prayers?

It is not permissible to offer the prayer before its appointed time, and a prayer performed before its time is not valid. The Lawgiver has made exceptions for certain situations, such as travel, rain, and hardship, permitting the combining and offering of the second of two conjoined prayers earlier. Accordingly, it is not permissible to offer the 'Asr prayer before its time for the sake of praying in the Grand Mosque (Haram Makkah), as the desire to multiply reward and the fear of missing out on that does not fall under the category of hardship or difficulty.