Volume 2, Book 13, Number 2:

Narrated ‘Abdullah bin Umar:

Allah’s Apostle (SallAllah-u-Alaihi-wa-Sallam) said, “Anyone of you attending the Friday (prayers) should take a bath.”
[Sahih Bukhari]

Volume 2, Book 13, Number 3:

Narrated Ibn ‘Umar:

While Umar bin Al-Khattab was standing and delivering the sermon on a Friday, one of the companions of the Prophet, who was one of the foremost Muhajirs (emigrants) came. ‘Umar said to him, “What is the time now?” He replied, “I was busy and could not go back to my house till I heard the Adhan. I did not perform more than the ablution.” Thereupon ‘Umar said to him, “Did you perform only the ablution although you know that Allah’s Apostle (SallAllah-u-Alaihi-wa-Sallam) used to order us to take a bath (on Fridays)?”
[Sahih Bukhari]

Volume 2, Book 13, Number 4:

Narrated Abu Said Al-Khudri:

Allah’s Apostle (SallAllah-u-Alaihi-wa-Sallam) said, “The taking of a bath on Friday is compulsory for every male (Muslim) who has attained the age of puberty.”
[Sahih Bukhari]

Prophet Muhammad [SallAllah-u-Alaihi-wa-Sallam] has ordered us to take baths on Fridays, What do you people think an order of the Nabi [SallAllah-u-Alaihi-wa-Sallam] is ?

There are sects in the Ummah who consider this action as Mustahab or Nafil only, even thou Allah’s apostle has said it is Farz [compulsory].