بسم الله الرحمن الرحيم

The Prophet (pbuh) said: Whoever says,
أستغفر الله الذي لا اله هو الحي القيوم وأتوب إليه

“Astaghfirullah al-lathi laa ilaha illa huwa, al-Hayyul Qayyum wa atubu ilayh” –
‘I ask forgiveness from Allah the One whom there is no deity worthy of worship except He, the Ever-Living and Sustainer and I repent to Him’
three times, Allah would forgive his sins even if they were as much as the foam of the sea. [Abu Dawud]