Bava Metzia 19B

הא בבריא, והא בשכיב מרע.

This halakha applies in a case of a gift given by a healthy person, and that halakha applies in a case of a gift given by a person on his deathbed.

מתניתין דקתני: הא אמר תנו נותנין ⁠– בשכיב מרע, דבר מהדר הוא.

The Talmud explains: The Mishnah that teaches that if the giver says: Give it to its intended recipient, the finder must give it, applies in a case of a gift given by a person on his deathbed, who is capable of retracting his gift.

דאמרינן, מאי איכא למימר: דלמא כתבה מעיקרא להאי ואמליך ולא יהבה ניהליה, והדר כתבה לאיניש אחרינא ויהביה ניהליה ⁠– השתא קא הדר ביה מההוא דיהבה ניהליה.

Therefore, the finder must give the deed to the recipient, as we say: What is there to say as a reason for not returning the deed? One might suggest that perhaps the giver initially wrote a deed of gift for this person, but then reconsidered and did not give it to him, and then he wrote a second deed of gift for another person and thereby gave his property to him. And now that his first deed was found, he wishes to retract his gift to that second person to whom he gave the property, by dishonestly validating the first deed.

אי במתנת בריא יהבה ליה ⁠– לית ליה פסידא, דכי נפקא תרתי, בתרייתא זכי, דהא הדר ביה מקמייתא.

This attempt to retract his latter gift will not succeed. If he gave his property to the recipient of the second deed of gift as the gift of a healthy person, then the second recipient incurs no loss by the first deed being given to its intended recipient. This is because, when the two deeds are produced in court, the recipient of the later one acquires the property, as the owner evidently retracted the first gift. Since one who gave away his property while on his deathbed can subsequently retract his gift, the second recipient acquires the property.