Sayyiduna Jabir (may Allah be pleased with him) says: Sulayk al-Ghatafani came while the Prophet (peace and blessings be upon him) was delivering the sermon, and he (peace and blessings be upon him) ordered him to pray two rak'ahs.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6678