Hazrat Abu Hurairah (May Allah be pleased with him) narrates that the Holy Prophet (Peace be upon him) said: be hasty in doing virtuous deeds before seven things happen. Don’t you wait for such a misery that would make you forgetful of everything or such affluence which makes you rebellious (against Allah) or such ailment which makes you lifeless or the old age which makes you insane or such death which comes suddenly (without leaving any chances for repentance) or the Antichrist (Dajjal) which is one the worst hidden evil or the Day of Judgement which is the harshest and bitterest of all. (Tirmidhi).