— Among its virtues is that it is the best of deeds, that its reward is multiplied most abundantly, that it is equivalent to freeing slaves, and that it protects the one who utters it from Satan. It is related in the two Sahih collections from Abū Hurayra—may Allah be pleased with him—that the Prophet—may Allah bless him and grant him peace—said: “Whoever says one hundred times in a day, ‘There is no deity worthy of worship but Allah alone, without partner. To Him belongs all sovereignty and all praise, and He has power over all things,’ will receive the equivalent of freeing ten slaves; one hundred good deeds will be recorded for him; one hundred sins will be erased from him; and no one will have done anything better than he has, except someone who did more than that.” 1
They also relate from Abū Ayyūb al-Ansārī—may Allah be pleased with him—that the Prophet—may Allah bless him and grant him peace—said: “Whoever says it ten times will be like one who freed four persons from the descendants of Ishmael.”2
— Another of its virtues is that it is the best thing uttered by the prophets. It is established in a hadith that the Prophet—may Allah bless him and grant him peace—said: “The best thing that the prophets and I have said late on the Day of Arafah is: ‘There is no deity worthy of worship but Allah alone, without partner. To Him belongs all sovereignty and all praise, and He has power over all things.’”3 Another wording states: “The best supplication is the supplication made on the Day of Arafah, and the best thing that the prophets before me and I have said is: ‘There is no deity worthy of worship but Allah alone, without partner. To Him belongs all sovereignty and all praise, and He has power over all things.’”4.