One of the Ten Commandments mandated that no work at all was to be done on the Sabbath. The day was sacred.
(‏ خروج ١٦ :‏ ​ ١٣ -‏ ٣٠‏ )‏ وَقَدْ حَرَّمَتْ إِحْدَى ٱلْوَصَايَا ٱلْعَشْرِ صُنْعَ عَمَلٍ مَا يَوْمَ ٱلسَّبْتِ لِأَنَّهُ يَوْمٌ مُقَدَّسٌ .‏