During the time of Musa Alaihis Salaam, the Bani Isra'il were afflicted with a severe drought. Together, they begged Allah for rain but it was of no avail. The heat became more intense and the skies remained cloudless.
Musa Alaihis Salaam then cried out to Allah, "O Allah, if my status is nothing to you then I beseech you by the grace of Muhammad Sallallahu Alaihi Wasallam to please grant us rain."
Allah sent a revelation down to him: "Your status is noble in My sight, however, there is person amongst you who has disobeyed Me for forty years. It is because of him that I am holding back the rains from you."
Musa Alaihis Salaam stood up and addressed the congregation, "O sinner who has disobeyed Allah for forty years, please leave this gathering."
The sinner said to himself, "If I stand up in this gathering to leave, the entire Bani Isra'il will realise that I am the guilty one." He lowered his head in shame and said, "O my Allah, I beg Your forgiveness."
Immediately the rain came down in torrents.
Musa Alahis Salaam asked, " O Allah, why did You send us rain?"
Allah replied, "Due to the sinner who repented."
Musa Alaihis Salaam asked, "O Allah, reveal his identity to me."
Allah answered, "When I did not reveal his condition as a sinner, how can I now expose him when he has sincerely repented?" (Nuzhatul Majalis)
1. Sins are an obstacle to the acceptance of dua.
2. Allah is Sattaar. He conceals the sins of man out of His kindness.
3. Allah is Ghafoor. He forgives the sins of man when man turns in repentence. When man repents sincerely Allah grants numerous bounties. The Quran says, "Ask forgiveness of your Lord. Verily He is Most Forgiving. He will send rain to you in abundance. And He will increase you in wealth and children and bestow on you gardens and rivers." (Surah Nooh, verse 10 - 12)