Chapter on the Reasons Behind Hajj
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 1
وَ إِنَّمَا سُمِّيَ اَلْحَجُّ اَلْأَكْبَرَ لِأَنَّهَا كَانَتْ سَنَةً حَجَّ فِيهَا اَلْمُسْلِمُونَوَ اَلْمُشْرِكُونَ وَ لَمْ يَحُجَّ اَلْمُشْرِكُونَ بَعْدَ تِلْكَ اَلسَّنَةِ ».
The Hajj was called 'Al-Hajj Al-Akbar' (the Greater Pilgrimage) because it was the year in which both Muslims and polytheists performed the pilgrimage, and the polytheists did not perform Hajj after that year.
- Ṣaḥīḥ al-Faqīh