حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا مُحَمَّدُ بْنُ أَبِي عُبَيْدَةَ، عَنْ أَبِيهِ، عَنِ الأَعْمَشِ، عَنْ أَبِي سُفْيَانَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالُوا يَا رَسُولَ اللَّهِ الْحَجُّ فِي كُلِّ عَامٍ قَالَ ‏"‏ لَوْ قُلْتُ نَعَمْ لَوَجَبَتْ وَلَوْ وَجَبَتْ لَمْ تَقُومُوا بِهَا وَلَوْ لَمْ تَقُومُوا بِهَا عُذِّبْتُمْ ‏"‏ ‏.‏

It wasnarrated that Anas bin Malik said: “They said: ‘O Messenger ofAllah, is Hajj (required) every year?’ He said: ‘If I were to sayyes,it would have become obligatory, and if it were to becomeobligatory,you would not (be able to) do it, and if you did not doit you wouldbe punished.’” Translation Not Available

Book Ref: Sunan Ibn Majah Book 25 Hadith 2885
Web Ref:  Sunan Ibn Majah Vol 4 Book 25 Hadith 2885