Muslim

Thauban (Radi Allah Anhu) reported:

Whenever the Messenger of Allah
(Sallallahu Alaihi Wasallam) concluded his prayer,
he would beg forgiveness from Allah thrice
and then would recite:

"Allahumma Antas-Salamu, wa minkas-salamu,
tabarakta ya Dhal-Jalali wal-Ikram"

("O Allah, You are the Grantor of security,
and security comes from You.
You are Blessing,
O You Who have majesty and nobility!'')

(Imam) Al-Awza`i, one of the narrators of this Hadith, was asked:
"How forgiveness is to be sought?''

He answered:
"The Messenger of Allah (Sallallahu Alaihi Wasallam) used to say:
'Astaghfirullah! Astaghfirullah! '

(I beseech Allah for forgiveness, I beseech Allah for forgiveness) '.''


[Muslim].