Du'a seeking Allaah's aid to repay debt

Ali رضي اللّه عنـه 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 رضي اللّه عنـه said to him, "Shall I not teach you a supplication which the Messenger of Allaah صلّى اللَّهُ عليه وسلّم taught me? It will surely prove so effective that if you have a debt as large as a huge mountain, Allaah سُبحانه وتعالى will surely pay it for you. Say:

'Allaahummakfini bi halaalika an haraamika, wa aghnini bi fadlika amman siwaka.'

 
"O Allaah! Make sufficient for me what is halaal (lawful) and to dispense with what is haram (unlawful) and enrich me with Your Favors so that I need no one but You."