It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: Although we came last, on the Day of Resurrection we will be the foremost. The only difference is that every nation was given the Book before us, while we received the Book later. Then this Friday was appointed by Allah for them, but they differed regarding it, so Allah guided us to it. Now, in this matter, people follow us, and the Jews have the next day (Saturday), and the Christians have the day after that (Sunday). Then, after remaining silent for a while, he said: It is Allah’s right upon every Muslim that he should wash his head and body every seven days.