Sulaym bin Hanzalah (may Allah have mercy on him) said: I recited a verse of prostration in the presence of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), so he looked at me and said: You are our imam; you prostrate so that we may prostrate with you.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3771