Musnad Ahmad Hadith 7159

It is narrated from Abu Huraira (may Allah be pleased with him) that a man came to the presence of the Prophet and said, "O Messenger of Allah! At what time is giving charity most rewarding?" The Noble Prophet (ﷺ) said: "By your father! You will surely get its answer. The best charity is that which you give while you are healthy, desiring wealth, fearing poverty, and hoping to live longer. Do not delay charity until the soul reaches the throat, and then you begin to say, 'Give this much to so-and-so and that much to so-and-so,' while it has already become the property of so-and-so (the heirs)."