Sahih Muslim Book - 1, Hadith - 377

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ وَمُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ وَأَبُو كُرَيْبٍ وَاللَّفْظُ لِأَبِي كُرَيْبٍ قَالُوا حَدَّثَنَا أَبُو مُعَاوِيَةَ عَنْ الْأَعْمَشِ عَنْ شَقِيقٍ عَنْ حُذَيْفَةَ قَالَ كُنَّا مَعَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ أَحْصُوا لِيْ كَمْ يَلْفِظُ الْإِسْلَامَ قَالَ فَقُلْنَا يَا رَسُولَ اللَّهِ أَتَخَافُ عَلَيْنَا وَنَحْنُ مَا بَيْنَ السِّتِّ مِائَةٍ إِلَى السَّبْعِ مِائَةٍ؟ قَالَ إِنَّكُمْ لَا تَدْرُونَ لَعَلَّكُمْ أَنْ تُبْتَلَوْا قَالَ فَابْتُلِيَنَا حَتَّى جَعَلَ الرَّجُلُ مِنَّا لَا يُصَلِّي إِلَّا سِرًّا.

It was narrated that Hudhaifah said: "We were with the Messenger of Allah (s.a.w) and he said: 'Tell me how many people have professed Islam.' We said: 'O Messenger of Allah, do you fear for us while we are between six hundred and seven hundred strong?' He said: 'You do not know, perhaps you will be tested.' He said: 'And we were tested, until some of us performed Salat only in secret."'