A) Hasan al Basri -Rahimullaah- mentioned: ‘That a man complained to him concerning drought so it was said seek forgiveness from Allaah, another complained about another matter so it was said seek forgiveness from Allaah, another complained about lack of rain for his land so it was said seek forgiveness from Allaah another complained of no offspring so it was said seek forgiveness from Allaah, then he (Hasan al Basri) recited.
ٱسۡتَغۡفِرُواْ رَبَّكُمۡ إِنَّهُۥ كَانَ غَفَّارٗا ١٠ يُرۡسِلِ ٱلسَّمَآءَ عَلَيۡكُم مِّدۡرَارٗا ١١ وَيُمۡدِدۡكُم بِأَمۡوَٰلٖ وَبَنِينَ وَيَجۡعَل لَّكُمۡ جَنَّٰتٖ وَيَجۡعَل لَّكُمۡ أَنۡهَٰرٗا ١٢ <> [Nuh: 10-12]
[Taken from: ‘Fath al-Bari’ Chapter: the Best Method of Seeking forgiveness]
B) al-Hafidh Emaad ad-Deen Isma’eel Ibn Katheer (d. 774 A.H.) -Rahimullaah- said in his Tafseer about the previous Ayaat:
‘If you repented to Allaah and sought forgiveness from Him and showed obedience to Him your Rizq (provision) would increase and rain would fall from the blessings of the skies, and the blessings of the earth would spring forth, crops would grow for you. You will be given abundant livestock. You will be aided with wealth and offspring; meaning that offspring and wealth would be given to you. And you will be given gardens that have numerous types of fruits and through out there will be rivers that flow in these gardens. This is the way of giving Dawa’ by encouragement.’ [Taken from: ‘Tafseer al-Qur’aan al-Atheem’ 4/p.536]
C) It is narrated from Abi Saeed Al-Khudri that the Messenger of Allaah -sallAllaahu alayhi wa sallam- said: ‘Whoever performs Wudu and then says: ‘ Subhanaka Allahuma wabihamdika la ilaha ila anta astaghfiruka wa atooboo ilaika’ (‘Far are You O Allaah from imperfection, and You have all praise, there is none worthy of worship in truth except You, I seek forgiveness from You and I repent to You), then this reward is written in a parchment and it is stamped with a seal and no falsehood can break it until the day of Judgment.’
[Taken from ‘Silsilah as-Saheehah’ No. 2333 declared Hasan by Shaykh al-Albaani]