It is narrated from Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) that two men from the people of Iraq came seeking a cure for their father, whose urine had been retained. The people directed them to Fadalah. The two of them came to Fadalah and mentioned their father's ailment, and Fadalah said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever among you suffers from something, or whose brother suffers, let him recite this supplication: 'Rabbana alladhi fi al-sama'i taqaddasa ismuka, amruka fi al-sama'i wa al-ard, kama rahmatuka fi al-sama'i wa al-ard, ighfir lana hubana wa khatayana ya Rabba al-tayyibin, anzil shifa'an min shifa'ika wa rahmatan min rahmatika 'ala hadha al-waja'' (Our Lord who is in the heaven, holy is Your name; Your command prevails in the heaven and the earth; just as Your mercy is in the heaven, (send it down) likewise upon the earth. O Lord of the pure, forgive us our sins and our faults; send down a healing from Your healing and a mercy from Your mercy upon this pain), and he will be cured." This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.