The answer
The word 'rest' here does not mean that God was tired and needed rest; but that He had finished the creation process. God created everything in six days. On the sixth day, He created man in His own image and according to His own likeness; and "Then God saw everything that He had made, and indeed it was very good" (Gen 1:31). God decided that He had completed His work and did not need to create anything else and so he rested. Until today we are still on the seventh day.Answered by His Eminence Metropolitan Youssef (opens in a new tab)