(a) It is narrated from Abu al-Aliyah al-Barra' that Abdullah bin Safwan (may Allah be pleased with him) asked Abdullah bin Umar (may Allah be pleased with him): O Abu Abd al-Rahman, do you recite in every prayer? He said: I feel shy before the Lord of this House, that is, the Ka'bah, to pray two rak'ahs in which I do not recite Surah al-Fatihah or more. In one narration the word is "fa-za'idan" (and more), and in another "fa-sa'idan" (and upwards).
(b) It is as though he considered reciting behind the imam correct only in the prayers in which the imam recites quietly, that is, the silent prayers. Malik bin Anas (may Allah have mercy on him) based (his position) on this; the opposite has also been narrated from him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2902