قَالَ النَّبِيُّ صلى الله عليه وسلم: ((خَيْرُ الدُّعَاءِ دُعَاءُ يَوْمِ عَرَفَةَ، وَخَيْرُ مَا قُلْتُ أَنَا وَالنَّبيُّونَ مِنْ قَبْلِي: لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ)).
Transliteration: The best of supplications is the supplication on the day of AAarafah and the best which I and the Prophets before me have said (is): (La ilaha illal-lahu wahdahu la shareeka lah, lahul-mulku walahul-hamd, wahuwa AAala kulli shayin qadeer.)
Translation: The best of supplications is the supplication on the day of AAarafah and the best which I and the Prophets before me have said (is): (None has the right to be worshipped except Allah, alone, without partner. To Him belongs all praise and sovereignty and He is over all things omnipotent.)