Abdullah bin Masūd (may Allah be pleased with him) relates that Allah’s Messenger (peace and blessings of Allah be with him) who is the most truthful (of the human beings) and his being truthful (is a fact) said: “Verily, your creation is on this wise. The constituents of one of you are collected for forty days in his mother’s womb in the form of blood, after which it becomes a clot of blood in another period of forty days. Then it becomes a lump of flesh and forty days later Allah sends His angel to it with instructions concerning four things, so angel writes down his livelihood, his death, his deeds, his fortune and misfortune. By Him, besides Whom there is no God, that one among you acts like the people deserving Paradise until between him and Paradise there remains but a distance of a cubit, when suddenly the writing of destiny overcomes him and he begins to act like the denizens of Hell, and thus enters Hell, and another one acts in the way of the denizens of Hell, until there remains between him and Hell a distance of a cubit that the writing of destiny overcomes him and then he begins to act like the people of Paradise and enters Paradise.”
(Sahih Muslim)
Destiny plays its role in man’s life. But man is not mere puppet in the hands of destiny. He is capable of doing both good and evil. If he shows a charitable disposition and guards against evil and adopts the path of righteousness, he would be facilitated to achieve good ends, but if he behaves otherwise, he would be led to ruin and destruction.
A person’s destiny is in the knowledge of God, Who knows it for certain which course he/she would adopt on such and such occasion, but the person is not forced to act in a specific way. What the hadith brings home to man is that nothing can be said about one’s ultimate end during one’s life.