It is narrated from Sayyiduna Talhah bin Ubaidullah bin Khariz (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The best supplication is the supplication of Arafah, and the best of what I and the prophets before me have said is «لَا إِلٰهَ إِلَّا اللّٰهُ وَحْدَهُ لَا شَرِيكَ لَهُ» ."