It is narrated from Wa'il al-Hadrami (may Allah be pleased with him) that he prayed behind the Prophet (peace and blessings be upon him). When he said: 'Nor of those who go astray' [Surah al-Fatihah: 7], he said: "Amin," and raised his voice. Like the narration of al-Thawri (may Allah have mercy on him), it has also been reported from Wa'il bin Hujr (may Allah be pleased with him) through two other routes.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2448