Musnad Ahmad 25:561

Abu Sa’id narrated to us, Sulayman ibn Bilal narrated to us, from ‘Amr—meaning Ibn Abi ‘Amr—from ‘Ikrimah, from Ibn ‘Abbas, that a man asked him about bathing on Friday: "Is it obligatory?" He said: "No, but whoever wishes may bathe. And I will tell you about the beginning of bathing: The people were in need, and they used to wear wool, and they used to water the palm trees on their backs. The mosque of the Prophet, may Allah bless him and grant him peace, was narrow with a low ceiling. So the people came in wool and sweated, and the pulpit of the Prophet, may Allah bless him and grant him peace, was short, consisting only of three steps. The people sweated in the wool, and their odors—the odors of the wool—rose up, and they annoyed one another, until their odors reached the Messenger of Allah, may Allah bless him and grant him peace, while he was on the pulpit. He said: 'O people, when you come to Friday, bathe, and let one of you apply the best perfume he has, if he has any.'"