Al-Aswad and Alqamah (may Allah have mercy on them both) say: We came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) at his house. He said: "Have these people prayed after you?" We said: No. He said: "Stand up and pray." He mentioned the complete hadith, in which it is stated that Sayyiduna Abdullah (may Allah be pleased with him) prayed together with al-Aswad and Alqamah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4995