The dua for seeking forgiveness is: 'Astaghfirullaha wa atubu ilayh' — I seek Allah's forgiveness and I repent to Him. Hz. Peygamber said he would seek forgiveness more than 70 times daily. A comprehensive version adds: 'Astaghfirullaha-lladhi la ilaha illa Huwal-Hayyul-Qayyum wa atubu ilayh.'
أَسْتَغْفِرُ اللَّهَ الَّذِي لَا إِلَٰهَ إِلَّا هُوَ الْحَيُّ الْقَيُّومُ وَأَتُوبُ إِلَيْهِ
Astaghfirullaha-lladhi la ilaha illa Huwal-Hayyul-Qayyumu wa atubu ilayh.
Meaning: I seek the forgiveness of Allah, there is no god but He, the Ever-Living, the Self-Sustaining, and I repent to Him.
Source: Sahih al-Bukhari #6307Istighfar brings immense blessings: relief from worries, a way out of difficulties, and provision from unexpected sources. Hz. Peygamber (sallallahu aleyhi ve sellem) said: 'Whoever adheres to seeking forgiveness, Allah will grant him relief from every worry, a way out from every hardship, and provide for him from sources he never imagined.' (Sunan Abu Dawud 1518)
أَسْتَغْفِرُ اللَّهَ الَّذِي لَا إِلَٰهَ إِلَّا هُوَ الْحَيُّ الْقَيُّومُ وَأَتُوبُ إِلَيْهِ
The Messenger of Allah (peace be upon him) said: 'By Allah, I seek the forgiveness of Allah and repent to Him more than seventy times a day.'