Musnad Abu Ya'la al-Mawsili 210:1

And with the chain of narration, he said: Abu al-Qasim Zahir ibn Tahir ibn Muhammad al-Shahhami informed us. Abu Sa’d Muhammad ibn Abd al-Rahman ibn Muhammad al-Janzarudhi informed us—reading to him while I listened—twice: once in Jumada al-Ula in the year four hundred and fifty-one, and once in Jumada al-Akhira of that same year. And the Shaykh Abu Bakr Muhammad ibn Muhammad ibn Hamdun al-Sulami [informed us]—reading to him on the first of Sha’ban in the year four hundred and fifty-three, with the reading of Shaykh Abu Salih al-Mu’adhdhin, may Allah have mercy on him. They both said: Abu ‘Amr Muhammad ibn Ahmad ibn Hamdan ibn ‘Ali ibn ‘Abd Allah ibn Sinan al-Hiri informed us. Al-Janzarudhi said, with the reading of Abu Ja’far al-‘Aza’imi in Rajab in the year three hundred and seventy-five, and he affirmed it and said: "Yes." Abu Ya’la Ahmad ibn ‘Ali ibn al-Muthanna al-Mawsili informed us: ‘Abd Allah ibn Muhammad ibn Asma’, the nephew of Juwayriyah, narrated to us: Juwayriyah narrated to us, from Nafi’, from ‘Abd Allah, from Hafsah, the Mother of the Believers, that the Messenger of Allah, may Allah bless him and grant him peace, used to pray two rak’ahs when the dawn broke.