Musannaf Ibn Abi Shaybah

Hazrat Abu Sa'id Khudri (may Allah be pleased with him) narrates that whoever, after completing ablution, says: "O Allah, I declare Your purity and praise You. I bear witness that there is no deity except You. I seek Your forgiveness and turn to You in repentance," then a seal is placed upon his words, and these phrases are preserved beneath the Throne. This seal will not be opened before the Day of Resurrection.