REWARD OF SINCERE WITNESSING H H 416 "Mu'az was riding pillion behind the Prophet, praise and peace be upon him, when the Prophet, praise and peace be upon him, called to him and he replied: 'Obedient with happiness and much help O Messenger of Allah, praise and peace be upon him,' He repeated this three times. Then the Prophet, praise and peace be upon him, said: 'For those worshipers of Allah who sincerely bear witness that there is no god except Allah, and that Muhammad is His worshiper and Messenger, Allah has forbidden the Fire for them!' Mu'az asked: "O Messenger of Allah, praise and peace be upon him, shall I tell everyone so that they may rejoice?' He replied: '(No,) perhaps they would depend upon this entirely.' When death approached Mu'az, he disclosed what the Prophet, praise and peace be upon him, had told him, fearing that he would be guilty of withholding some of the knowledge he had been given." R 416 Bukhari and Muslim with a chain up to Anas who related this hadith
415- وعن أنس رضي الله عنه : أن النَّبيّ صلى الله عليه وآله وسلم ومعاذ رديفه عَلَى الرَّحْل ، قَالَ : "يَا مُعَاذُ" قَالَ : لَبِّيْكَ يَا رَسُول الله وَسَعْدَيْكَ ، قَالَ : "يَا مُعَاذُ" قَالَ : لَبَّيْكَ يَا رَسُول الله وَسَعْدَيْكَ ، قَالَ : "يَا مُعَاذُ" قَالَ : لَبِّيْكَ يَا رَسُول الله وسَعْدَيْكَ ، ثَلاثاً ، قَالَ : "مَا مِنْ عَبْدٍ يَشْهَدُ أن لا إلهَ إلاَّ الله ، وَأنَّ مُحَمَّداً عَبْدُهُ وَرَسُولُهُ صِدْقاً مِنْ قَلْبِهِ إلاَّ حَرَّمَهُ الله عَلَى النَّار" قَالَ : يَا رَسُول الله ، أفَلاَ أخْبِرُ بِهَا النَّاس فَيَسْتَبْشِروا ؟ قَالَ : "إِذاً يَتَّكِلُوا" فأخبر بِهَا مُعاذٌ عِنْدَ موتِه تَأثُّماً . مُتَّفَقٌ عَلَيهِ . وقوله : "تأثُّماً" أي خوفاً مِنْ الإثم في كَتْم هَذَا العلم .