Sayyidah Umm Salamah (may Allah be pleased with her) narrates: Before his passing, the Prophet (peace and blessings be upon him) would frequently recite:
'Subhanaka Allahumma wa bihamdika, astaghfiruka wa atubu ilayk'
(Glory be to You, O Allah, and praise is Yours; I seek Your forgiveness and turn to You in repentance).
The Prophet (peace and blessings be upon him) said: "I have been commanded to do so." Then he recited this surah:
"When the help of Allah and the victory come" [al-Nasr: 1].
Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators are the narrators of the Sahih; and Allah knows best.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأذكار / 17168