Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) was asked: Which charity is best? He (peace and blessings be upon him) said: "You will certainly be informed of it: that you give charity while you are healthy and covetous of it, wishing to keep it and fearing poverty. So do not wait until your soul reaches your throat and then you say: 'So much is for so-and-so, and so much is for so-and-so.' Beware! It has by then already become so-and-so's." (Imam Muslim narrated it in his Sahih via Zuhayr bin Harb, and Imam Bukhari narrated it through other chains.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7832
Abu Habibah (may Allah have mercy on him) said: A man bequeathed to me a portion of his wealth for me to place (where it should go). So I came to Abu al-Darda (may Allah be pleased with him) and sought his advice about (giving it to) the poor or the Muhajirun. He said: As for me, if I were (in your place), I would not consider anyone equal to the Muhajirun. I heard the Messenger of Allah (peace and blessings be upon him) say: "The example of one who frees (a slave) at the time of death is like one who gives a gift after he has eaten his fill."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7833
Sayyiduna Abu al-Darda (may Allah be pleased with him) said: I heard the Prophet (peace and blessings be upon him) say: "The example of one who gives charity or frees (a slave) at the time of death is like one who gives (a gift) after he has eaten his fill."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7834
Murrah (may Allah have mercy on him) said that Abdullah (may Allah be pleased with him) said, concerning the words of Allah Almighty: "And gives wealth, despite his love for it, to relatives, orphans and the needy" [Surah al-Baqarah: 177]: Give charity while you are healthy and covet wealth, hoping to become rich and fearing poverty.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7835