Imam Baqir (a.s) said:
 الحَجُّ والعُمرَةُ سوقَانِ من أسواقِ الآخِرَةِ؛ اللازِمُ لهُما مِن أضْيافِ اللهِ تعالى. إِنْ أبقَاهُ، أبقاهُ وَلا ذَنبَ لهُ، وإنْ أَماتَهُ، أَدخَلَهُ الجَنّةَ.
Hajj and Umrah are two markets of the Hereafter. Those who enter into them are Allah's guests. If Allah preserves his guest's life, he will live free from sins and if He makes him die, he will be admitted into Paradise. ( See al-Wafi, Vol. 2)