Jami' at-Tirmidhi 3420

Abu Salamah said:

“I asked Aishah [may Allah be pleased with her]: ‘With what did the Prophet used to open his Salat when he stood up in the night?’ She said: ‘When he stood up in the night, he would open his Salat by saying: “O Allah, Lord of Jibra’il, Mika’il, and Israfil; Originator of the heavens and the earth, [and] Knower of the hidden and the seen; You judge between Your slaves concerning that which they used to differ, guide me through that which there has been difference concerning the truth, verily, You are upon a straight path (Allāhumma rabba Jibrīla wa Mīkā'ila wa Isrāfīl, fāṭira-samāwāti wal-arḍi [wa] `ālimal-ghaibi wash-shahādati anta taḥkumu baina `ibādika fīmā kānū fīhi yakhtalifūn, ihdini limakhtulifa fīhi minal-ḥaqqi bi'idhnika innaka tahdī man tashā'u ilā ṣirātin mustaqīm).”