In the name of Allah, Most Gracious, Most Merciful.
Abu Hurairah (May Allah be pleased with him) said: There came a man to the Prophet (SAWS) and said: “O Messenger of Allah, which charity is the most rewardable?” The Prophet (SAWS) said: “That you should give charity (in a state when you are) healthy and stingy and fear of poverty, hoping to become rich (charity in such a state of health and mind is the best). And you must not defer (charity to such a length) that you are about to die and would be saying: “This is for so-and-so, and this for so-and-so.” Lo! It has already come into (the possession of) so-and-so”. (Al-Bukhari and Muslim)
Commentary: Charity in the real sense is that which a person gives when he is healthy. If a person gives charity when he is facing death, it does not have much value before Allah. This injunction is an inducement for people to hurry in doing good deeds, especially in the matter of alms and charity. In fact, he should do it without delay.
SAWS: May Allah exalt his mention and protect him from imperfection
Riyaadiss-Saliheen (The Meadows of the Righteous)
By Imam An Nawawi
Chapter 10, Page 35, No 90