Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates from the Messenger of Allah (peace and blessings be upon him) that he (peace and blessings be upon him) said: "Indeed, a man does the deeds of the people of Paradise for a long time, then Allah Almighty seals his deeds with the deeds of the people of the Fire, and so He makes him one of the people of the Fire. And indeed, a man does the deeds of the people of the Fire for a long time, then Allah Almighty seals his deeds with the deeds of the people of Paradise, and so He makes him one of the people of Paradise."
Hadith Referenceالمعجم الأوسط / باب الألف / 2780
Hadith Takhrij«أخرجه مسلم فى «صحيحه» برقم: 2651، وابن حبان فى «صحيحه» برقم: 6176، وأحمد فى «مسنده» برقم: 10429، والبزار فى «مسنده» برقم: 8198، 8317، والطبراني فى «الأوسط» برقم: 2448»