Is the sin committed by a human being predestined and inscribed upon him, and will he enter Hellfire because of it, based on Omar Khayyam's saying: "God knew all our deeds from the day He molded our clay and created us. We commit no sin without His decree, so why then do we enter the Fires?"?

All that occurs in the universe, be it good or evil, has been written and ordained by Allah since eternity. Allah knew from eternity what His servants would do before He created them, and He has given them will, power, and intention. The evidence for this is His saying, the Almighty: "So whoever wills - let him believe; and whoever wills - let him disbelieve," and "For it is what it has earned, and upon it what it has incurred." And man perceives the difference between what he does by his own choice and what he does without his choice. However, the servant's will and power occur by the will of Allah the Almighty. And since the servant has intention and will, he is held accountable for what falls under his choice and will.