Messenger as a companion rider. Allah's Messenger said, "O Mu'adh bin Jabal." Mu'adh replied, "Labbaik and Sa'daik, (1) O Allah's Messenger!" Again the Prophet said, "O Mu'adh!" Mu'adh said thrice, "Labbaik and Sa'daik, O Allah's Messenger!" Allah's Messengerﷺ said, "There is none who testifies sincerely from his heart that La ilaha illallah wa anna Muhammad-ar-Rasul Allah" (none has the right to be worshipped but Allah and Muhammad is the Messenger of Allah), except that Allah will save him from the Hell-fire." Mu'adh said, "O Allah's Messenger! Should I not inform the people about it, so that they may have glad tidings?" He replied, "When (the people hear about it), they will solely depend on it." Then Mu'adh narrated the above mentioned Hadith just before his death, being afraid of committing a sin (by concealing the knowledge).
Sahih Bukhari
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