In the Torah, we find the words:
Six days may work be done; but in the seventh is the Sabbath of rest, holy to the Lord: whosoever does any work in the Sabbath day, he shall surely be put to death. (Exodus 31:15)
In the Noble Qur’ān, however, the Sabbath is not reinforced. The Torah clearly states that it is a sign between God and the Israelites forever (as well as Passover), yet this is not stated in the Qur’ān. Why is Sabbath not the Muslims?
Sabbath, no doubt, is a day of great importance but for the Israelites as you have mentioned. Allah declared for each nation a special day in order to distinguish them from others and to give them a feeling of personal relationship with Allah. This relationship they experience on the day appointed divinely for them.
As far as the Muslims are concerned, the Prophet (sws) has given importance to Friday. On this day, they proclaim the greatness of Allah in large gatherings as compared to normal congregation for other obligatory prayers. This difference is same as the difference of ‘Eīd (feast) days. Muslims celebrate and enjoy feasts on days different from those appointed for the People of the Book. Thus, there was no need to reinforce the importance of Sabbath in the Holy Qur’ān.