Source: Ikhtiyar al-Misbah by Sayyid Ibn Baqiy (d. 653 AH) according to the transmission in Bihar Al-Anwar
Dua Al-Ṣabāḥ was a hymn that has been reported to have been recited by the Commander of the Faithful Ali ibn Abi Talib after dawn (fajr) prayer. According to some Shi'a scholars, this supplication contains the highest spiritual, mystical, and theological teachings in a very eloquent style.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيمِِ
bismi llāhi ar-raḥmāni ar-raḥīm
In the Name of Allah, the Beneficent, the Merciful.
أَللَّهُمَّ صَلِّ عَلى مُحَمَّدٍ وَّ آلِ مُحَمَّد
allāhumma ṣalli ʿalā muḥammadin wa āli muḥammad
O Allah! Bless Muhammad and his progeny.
اَللّـهُمَّ يا مَنْ دَلَعَ لِسانَ الصَّباحِ بِنُطْقِ تَبَلُّجِهِ
allāhumma yā man dalʿa liṣāna ṣ-ṣabāḥi binuṭqi taballujihī
Oh God, Oh He who extended the morning's tongue in the speech of its dawning