It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him) ordered me to announce: "There is no prayer without the recitation of Surah al-Fatihah, though more than that may be recited."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2456