Nafi' said: Ibn Umar (may Allah be pleased with them both) used to lengthen the prayer before the Friday prayer and pray two rak'ahs at home after it, and he would say: "This is how the Prophet (peace and blessings be upon him) used to do."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5943