Yahya related to me from Malik from Abu Nuaym Wahb ibn Kaysanthat he heard Jabir ibn Abdullah say, "Someone who prays a rakawithout reciting the umm al-Qur'an in it has not done the prayerexcept behind an imam." (ID)
App reference (ID): Book 3, Hadith 40 (ID)
USC-MSA web (English) reference: Book 3, Hadith 40 (ID)
Arabic reference (ID): Book 3, Hadith 187 (ID)