Abdullah bin Rabi'ah said: We were with Abdullah bin Mas'ud (may Allah be pleased with him). The people mentioned a man and spoke about his character, and the people said: "Is there no one to restrain him?" Abdullah (may Allah be pleased with him) said: "What do you think, if his head were cut off, could you make a head for him? Or if his two hands were cut off, could you make a hand for him? Or if his foot were cut off, could you make a foot for him?" They said: "No." Then Abdullah (may Allah be pleased with him) said: "Indeed, when the drop of semen falls into the woman, it remains for forty days, then it descends as blood, then it becomes an 'alaqah, then likewise it becomes a mudghah. Then Allah sends the angel and says: 'Write down his lifespan, his deeds, his provision and his traces, and whether he is wretched or fortunate.' So you will never be able to change his character until you change his physical form."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8853