Hadithcore
Mishkat al-Masabih, 2415

‘Abd ar-Rahman b. Abza told that God's messenger used to say in the morning, “We have reached the morning following the original religion of Islam, the assertion of God’s unity, the religion of our Prophet (ﷺ) Muhammad, and the rite of our father Abraham who was a <i>hanif</i> and was not one of the polytheists." [cf. Qur’an, ii. 135; iii, 95; vi, 161; xvi, 123.] Ahmad and Darimi transmitted it.

وَعَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبْزَى قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ إِذَا أَصْبَحَ: «أَصْبَحْنَا عَلَى فِطْرَةِ الْإِسْلَامِ وَكَلِمَةِ الْإِخْلَاصِ وَعَلَى دِينِ نَبِيِّنَا مُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَعَلَى مِلَّةِ أَبِينَا إِبْرَاهِيمَ حَنِيفًا وَمَا كَانَ مِنَ الْمُشْرِكِينَ» . رَوَاهُ أَحْمَدُ وَالدَّارِمِيُّ

References1 variant
In-Book Reference
Book 9, Hadith 185