Narrated Abu Al-Bukhtari:

from 'Ali who said: "When (the following) was revealed: And Hajj to the House is a duty that mankind owes to Allah, for those who are able to undertake the journey (3:97). They said: 'O Messenger of Allah! Every year?' But he was silent. So they said: 'O Messenger of Allah! Every year?' He said: 'No. If I were to say yes, then it would be required.' And Allah, Mighty and Sublime is He, revealed O you who believe! Ask not about things which, if made plain to you, may cause you trouble (5:101)."

حَدَّثَنَا أَبُو سَعِيدٍ الأَشَجُّ، حَدَّثَنَا مَنْصُورُ بْنُ وَرْدَانَ، عَنْ عَلِيِّ بْنِ عَبْدِ الأَعْلَى، عَنْ أَبِيهِ، عَنْ أَبِي الْبَخْتَرِيِّ، عَنْ عَلِيٍّ، قَالَ لَمَّا نَزَلَتْ : ( وَلِِلَّهِ عَلَى النَّاسِ حِجُّ الْبَيْتِ مَنِ اسْتَطَاعَ إِلَيْهِ سَبِيلاً ) قَالُوا يَا رَسُولَ اللَّهِ فِي كُلِّ عَامٍ فَسَكَتَ قَالُوا يَا رَسُولَ اللَّهِ فِي كُلِّ عَامٍ قَالَ " لاَ وَلَوْ قُلْتُ نَعَمْ لَوَجَبَتْ " . فَأَنْزَلَ اللَّهُ : ( يَا أَيُّهَا الَّذِينَ آمَنُوا لاَ تَسْأَلُوا عَنْ أَشْيَاءَ إِنْ تُبْدَ لَكُمْ تَسُؤْكُمْ ) .

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ مِنْ حَدِيثِ عَلِيٍّ . وَفِي الْبَابِ عَنْ أَبِي هُرَيْرَةَ وَابْنِ عَبَّاسٍ .