The heart cannot be sound unless it is completely free of shirk, which is contrary to Tawhid, because the worst type of wrongdoing and evil in this world is shirk or associating others with Allah, for that is the cause of a person abiding forever in the Fire. In this hadith, Anas (may Allah be pleased with him) narrates that the Prophet (blessings and peace of Allah be upon him) told Mu‘adh (may Allah be pleased with him) that whoever dies as a believer, associating nothing with Allah, in the sense that he worships Allah alone, knowing that none is rightfully worshipped except Him, and believing this in his heart, as indicated by these reports, will enter Paradise by the grace of Allah, either straight away or after being punished, but this does not include the hypocrites. Mu‘adh (may Allah be pleased with him) asked him to let him tell the people about that so that they might rejoice and be of good cheer, but the Prophet (blessings and peace of Allah be upon him) told him not to do that, for fear that they would rely on that and would strive less and do fewer acts of worship. According to the report narrated by al-Bukhari, Mu‘adh (may Allah be pleased with him) narrated this hadith just before he died, for fear of falling into the sin of withholding knowledge. This hadith highlights the virtue of Tawhid and the danger of shirk. It indicates that that there are some types of knowledge that may be told to all people, and some types that may be given only to the elite. It highlights the status and knowledge of Mu‘adh ibn Jabal (may Allah be pleased with him), because the Prophet (blessings and peace of Allah be upon him) told some knowledge exclusively to him. It indicates that it is prescribed for the seeker of knowledge to ask about that concerning which he is not certain. It also gives great glad tidings to those who affirm the oneness of Allah..