Riyad us-Saliheen

'Ali (May Allah be pleased with him) reported: A slave who had made a contract with his master to pay for his freedom, came to me and said: "I am unable to fulfill my obligation, so help me." He said to him: "Shall I not teach you a supplication which the Messenger of Allah (ﷺ) taught me? It will surely prove so effective that if you have a debt as large as a huge mountain, Allah will surely pay it for you. Say: 'Allahumm-akfini bihalalika 'an haramika, wa aghnini bifadlika 'amman siwaka (O Allah! Grant me enough of what You make lawful so that I may dispense with what You make unlawful, and enable me by Your Grace to dispense with all but You)."

'Imran bin Husain (May Allah be pleased with them) reported: The Prophet (ﷺ) taught my father two statements to recite in his Du'a. These are: "Allahumma al-himni rushdi, wa a'idhni min sharri nafsi (O Allah! Inspire in me guidance and deliver me from the evils within myself)."

Shahr bin Haushab reported: I asked Umm Salamah (May Allah be pleased with her), "O Mother of the Believers! Which supplication did the Messenger of Allah (ﷺ) make frequently when he was in your house?" She said: "He (ﷺ) supplicated frequently: 'Ya muqallibal-qulubi, thabbit qalbi 'ala dinika (O Controller of the hearts make my heart steadfast in Your religion)."