The Hadith mentions the entire method together with the Du'aa to be recited for Salaatul Haajat. Nabi (Sallallaahu Alayhi Wasallam) mentions, "Whoever has any need, then firstly, perform a proper Wudhu, thereafter perform 2 Rakaats Salaat (reciting whichever Surahs one desires). Thereafter, commence your Du'aa by praising Allah and sending salutations upon Nabi (Sallallaahu Alayhi Wasallam)."
Recite the following Du'aa, "Laa ilaaha illallaahul haleemul kareem. Subhaanallaahu rabbil arshil adheem, alhamdulillaahi rabbil `aalameen. As-aluka muwjibaat rahmatika, wa `adhaaima maghfiratika wal ghaneemat min kulli birr was salaamat min kulli ithm, laa tada`a liy dhanban illaa ghafaratah walaa hamman illaa farrajtah walaa haajatan hiya laka ridhan illaa qadhaytahaa Yaa arhamar raahimeen" (Trans: There is no deity besides Allah who is most tolerant and most noble. Glory be to Allah Who is the Lord of the majestic throne. All praises are for Allah, the lord of the Universe. I am asking you O Allah to bestow upon me Your mercy and forgiveness, grant me piety and protection from all misfortunes. Do not leave any sin on me except that you forgive me, relieve me from distress and difficulties and fulfil all such needs of mine which You are pleased with - O Most Merciful of those who show mercy.) (Tirmidhi pg.108; Ashrafiyya)
Together with performing this Salaat, one should always keep in mind that help and assistance comes only from Allah Ta'ala. Allah grants to whomsoever He wishes and withholds from whomsoever He wishes. If one's needs are not fulfilled, do not ever become despondent in the mercy of Allah because Allah is the most wise and know best the reason of withholding one's Du'aas and needs.
and Allah Ta'ala Knows Best
Mufti Ebrahim Desai, www.ask-imam.com
