Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) says: Sulayk bin Amr al-Ghatafani entered the mosque while the Prophet (peace and blessings be upon him) was standing on the pulpit delivering the sermon on Friday, and the Prophet (peace and blessings be upon him) said to him: "Have you prayed?" He said: No. He (peace and blessings be upon him) said: "Then pray two rak'ahs."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6679