Any Muslim or Imam which preaches against the Holy Sabbath is outside of true Islam. They are in a state of apostasy according to the Quran and will face Judgement. The Sabbath is a legally binding law enjoined on all people and animals created by God. If animals are to rest how much more the people of the world?
As the video reveals there are Islamic sects or families who observe the Biblical Sabbath. The Prophet Muhammed obeyed the Jewish fast of 10 Tevet (known as 10 Muharrum). His uncle could understand "Hebrew".
Sabbath in Islam