Musnad Abu Ya'la al-Mawsili 3:319

Abu Khaythama narrated to us, Ibn 'Uyaynah narrated to us, he said: Ibn Abi Layla narrated to me, from 'Amr ibn Murrah, from 'Abdullah ibn Salamah, from 'Ali, from the Prophet (may Allah bless him and grant him peace): That nothing would prevent him from reciting the Qur'an except for sexual impurity (janabah).