It is reported from al-Azraq bin Qays: I prayed behind Ibn al-Zubayr (may Allah be pleased with them both). He recited, and he recited 'In the name of Allah, the Most Gracious, the Most Merciful' [Surah al-Fatihah: 1] aloud.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2407