in which he teaches that once an intention is voiced, even though it has yet to come to pass, it is as though it has been fulfilled
"This being the case, if a dying person (lit. bedridden by illnes) voiced instructions and said: Whatever this tree produces is for the poor, or all income from this house is for the poor – it belongs to the poor. There are Geonim who disagree on this matter. Since poor people can receive only what can be obtained, they cannot receive what has yet to come into this world, but I tend to disagree. For a person does not instruct that something be obtained, but does instruct that his words concerning charity or trust be fulfilled just as one instructs to fulfill a vow." The Rabbi (author o)] Kessef Mishneh, as does the Beit Yoseph in Hoshen Mishpat 212, asks: How can the poor obtain anything if heirs make no oaths and those who bequeath to them are not in this world? He explains that since they overheard (the commitment) and remained silent, it is as though they received in order to give. End quote. With all due respect, it is a weak reason, and the commentary, of blessed memory, wrote that the reason is to fulfill the dying person's words. In my modest opinion, since we have the words of the dying person in writing or similarly submitted, or when a dying person voices such a thing, it is as though it were already handed to poor people. This is why our master mentions the law concerning what is obtained by poor people from a bedridden person, and all the more so for a healthy one.
Ma'asseh Rokach, Volume Four, Halakha 16, p.268, Samuel Akiva Schlesinger, Tel Aviv, 1974