For Asking Forgiveness and entrance to Paradise .
The virtues of seeking forgiveness are no secret, for it is the means of attaining forgiveness and entering Paradise, and it is the means of being granted a good life, increasing one’s strength, warding off disasters, making things easier, bringing rain and increasing one’s wealth and children.
'Asstaghfirulah allathe lailaha ila huwa, al hiyoul qaiyoum wa atubu ilay he.'
(I seek the forgiveness of Allah the Mighty, Whom there is none worthy except Him, the Living, The Eternal, and I repent unto Him)Whoever says the above words, Allah will forgive him even if he deserted the army's ranks.Ref :(Abu Dawud 2/85, at-Tirmidhi 5/569, Al-Hakim who declared it authentic and adh-Dhahabi agreed with him 1/511)
Another narration states that :
"Whoever recites three times on Friday morning before the Fajr prayer,
استغفر الله الذي لا اله الا هو الحي القيوم و اتوب اليه
(I ask forgiveness from Allah who is the Only God, the Living and Qayuum and repent to Him)
...Allah would forgive his sins even if they were as much as the foam of the sea." (Ibn Alsani)