It is narrated from Sayyiduna Abu Sa'id (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever performs ablution on Friday has done well, and whoever takes a ritual bath, then the ritual bath is better."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1416