Sayyiduna Salamah bin al-Akwa' (may Allah be pleased with him) narrates: Whenever I heard the Prophet (peace and blessings be upon him) begin a supplication, it was rare that I did not hear him (peace and blessings be upon him) begin it with: 'Subhana Rabbiyal-A'la al-Wahhab' (Glory be to my Lord, the Most High, the Bountiful Giver).
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6226