Musnad Abu Ya'la al-Mawsili 1:70

Al-Abbas ibn al-Walid al-Narsi narrated to us, Umar ibn Ali narrated to us, Abd al-Rahman ibn Ziyad ibn An'am narrated to us, he said: I heard Malik ibn Qays narrating, he said: Uqbah ibn Amir arrived to Mu'awiyah while he was in Iliya. He did not stay long before he went out, so he was sought but not found, or he said: We sought him but did not find him. So we followed him, and there he was, praying in an open space of land. He said: So he said, "What brought you?" They said, "We came to renew our acquaintance with you or to fulfill your right." He said, "Then I have your reward: We were with the Messenger of Allah (may Allah bless him and grant him peace) on a journey, and it was upon every man among us to tend the camels for a day. It was my day to tend them." He said: "So I brought the camels back in the evening and reached the Prophet (may Allah bless him and grant him peace) while his companions were surrounding him, and he was speaking." He said: "So I neglected the camels and headed toward him, and I reached him while he was saying: 'Whoever performs ablution and performs the ablution well, then prays two rak'ahs, intending by them the Face of Allah, Allah will forgive him what preceded them.'" I said, "Allah is the Greatest." He said: "Then a man struck my shoulder, so I turned around, and it was Abu Bakr. He said, 'O son of Amir, what was before them is better.' I said, 'What was before them?' He said: 'The Messenger of Allah (may Allah bless him and grant him peace) said: Whoever testifies that there is no god but Allah, his heart confirming his tongue, will enter from whichever of the gates of Paradise he wishes.'"