Sayyiduna Abu Hurayrah (may Allah be pleased with him) relates: The Prophet (peace and blessings be upon him) and I went out, with his (peace and blessings be upon him) blessed hand in my hand. A man of shabby appearance came to him. The Prophet (peace and blessings be upon him) said: O Abu so-and-so, how did you come to this state that I see? He said: Because of illness and poverty, O Messenger of Allah. The Prophet (peace and blessings be upon him) said: Shall I not teach you words through which Allah Almighty will remove illness and poverty from you? He said: No! In exchange for those two (that is, illness and poverty), I would not even like to have taken part with you in the Battle of Badr and the Battle of Uhud. The narrator says: The Prophet (peace and blessings be upon him) laughed, and he (peace and blessings be upon him) said: Can the people of Badr and the people of Uhud reach the rank which a contented poor man reaches? The narrator says: Sayyiduna Abu Hurayrah (may Allah be pleased with him) then said: O Messenger of Allah, teach them to me! The Prophet (peace and blessings be upon him) said: O Abu Hurayrah, recite: 'Tawakkaltu 'ala al-hayy alladhi la yamut, al-hamdu lillahi alladhi lam yattakhidh waladan wa lam yakun lahu sharikun fi al-mulk wa lam yakun lahu waliyyun min al-dhull, wa kabbirhu takbira' (I have put my trust in the Ever-Living who will never die; all praise belongs to Allah, who is free of offspring, who has no partner in sovereignty, and who is not weak so as to need a helper; and proclaim His greatness fully). The narrator says: Then once the Prophet (peace and blessings be upon him) came to me, and my condition had improved. He (peace and blessings be upon him) asked: What is the reason for this? I said: O Messenger of Allah, I keep reciting the words that you taught me.
Abu Ya'la recorded it; its chain contains Musa bin Ubaydah al-Rabadhi, who is da'if (weak) and has been weakly declared trustworthy, and also Harb bin Maymun; the rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 17882