Sayyiduna Abu al-Mundhir al-Juhani (may Allah be pleased with him) states: I said: "O Prophet of Allah, teach me the most excellent speech!" The Prophet (peace and blessings be upon him) said: "O Abu al-Mundhir, recite: 'La ilaha illallahu wahdahu la sharika lahu, lahul-mulku wa lahul-hamdu, yuhyi wa yumitu, biyadihil-khayru, wa huwa 'ala kulli shay'in qadir' (There is no deity except Allah; He is One, He has no partner; to Him alone belongs the dominion, to Him alone belongs all praise; He gives life and He gives death; all good of every kind is in His hand, and He has power over all things). (the Prophet, peace and blessings be upon him, says:) Recite these words one hundred times every day, and on that day you will be the most excellent of people in deeds, except for one who recited this phrase as many times as you recited it. Recite abundantly 'Subhanallah, wal-hamdu lillah, wa la ilaha illallah, wa la hawla wa la quwwata illa billah' (Glory be to Allah, all praise is for Allah, there is no deity except Allah, and there is no power and no strength except with Allah), for it is the chief of seeking forgiveness, and it erases sins." The narrator is in doubt; perhaps the narration also contains these words: "They make Paradise obligatory."
Bazzar recorded it; its chain contains a narrator, Jabir al-Ju'fi, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأذكار / 16842