Sayyiduna Uqbah bin Amir (may Allah be pleased with him) says: We had the duty of tending camels. Once my turn came, and I left them to graze. Then I found the Messenger of Allah (peace and blessings be upon him) standing, talking to people, and I learned this from him (peace and blessings be upon him): "Any Muslim who performs ablution well, then stands and offers two rak'ahs, turning to them with his face and his heart, Paradise becomes obligatory for him." The narrator says: I said: How excellent this is!
A man in front of me was saying that he (peace and blessings be upon him) had said something even better than this before.
I looked, and it was Sayyiduna Umar bin al-Khattab (may Allah be pleased with him). He said: I saw you arriving just now. He (peace and blessings be upon him) had said: "When any of you performs ablution and then says: 'Ashhadu an la ilaha illallah wa ashhadu anna Muhammadan abduhu wa rasuluh' (I bear witness that there is no god worthy of worship except Allah, and I bear witness that Muhammad (peace and blessings be upon him) is His servant and His Messenger),
the eight gates of Paradise are opened for him, and he may enter through whichever he wishes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 368
Sayyiduna Uqbah bin Amir (may Allah be pleased with him) heard Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) saying that the Messenger of Allah (peace and blessings be upon him) said: "Whoever performs ablution well and then says: 'Ashhadu an la ilaha illallah wahdahu la sharika lahu, wa anna Muhammadan abduhu wa rasuluh' (I bear witness that there is no god worthy of worship except Allah, alone, without partner, and that Muhammad is His servant and His Messenger), the eight gates of Paradise are opened, and he may enter through whichever he wishes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 369
In the hadith of Sayyiduna Ibn Umar and Anas (may Allah be pleased with them both) it is mentioned:
'Allahumma-j'alni mina-t-tawwabina wa-j'alni mina-l-mutatahhirin'
(O Allah, make me among those who repent much and make me among those who purify themselves.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 370