Chapter on Virtues of Hajj
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 2
وَ رُوِيَ عَنِ اَلنَّبِيِّ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ قَالَ: «اَلْحَجَّةُ ثَوَابُهَا اَلْجَنَّةُ وَ اَلْعُمْرَةُ كَفَّارَةُ كُلِّ ذَنْبٍ وَ أَفْضَلُ اَلْعُمْرَةِ عُمْرَةُ رَجَبٍ ».
It is narrated from the Prophet, peace and blessings be upon him and his family: "The reward for Hajj is Paradise, and Umrah is an expiation for all sins. The best Umrah is the Umrah performed in the month of Rajab."
- Ṣaḥīḥ al-Faqīh