Sahih al-Bukhari, Book 25, Hadith 7 (In-Book) ⓘ
Narrated Abu Huraira: The Prophet was asked, "Which is the best deed?" He said, "To believe in Allah and His Apostle." He was then asked, "Which is the next (in goodness)?" He said, "To participate in Jihad in Allah's Cause." He was then asked, "Which is the next?" He said, "To perform Hajj-Mabrur. "
حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ سُئِلَ النَّبِيُّ صلى الله عليه وسلم أَىُّ الأَعْمَالِ أَفْضَلُ قَالَ " إِيمَانٌ بِاللَّهِ وَرَسُولِهِ ". قِيلَ ثُمَّ مَاذَا قَالَ " جِهَادٌ فِي سَبِيلِ اللَّهِ ". قِيلَ ثُمَّ مَاذَا قَالَ " حَجٌّ مَبْرُورٌ ".
also referenced under: Hadith 1519 (DarusSalam) & Volume 2, Book 26, Hadith 594 (USC-MSA)