Bava Batra 136A

כדאמר רב חסדא: ״וקנינא מיניה מוסיף על מתנתא דא״; הכא נמי ⁠– דאמר: ״אף כתובו וחתומו והבו ליה״.

It is as Rav Ḥisda says that if it is written in the will: And we acquired it from him through an act of acquisition in addition to this gift, this formulation does not cancel the will’s power to take effect after the person’s death, as the intention of referring to it as a gift is merely to enhance the legal power of the recipient by confirming the transfer through an act of acquisition. Here too, in a case where he says: Write and sign a document as well, and give it to him, it is apparent that his request is to enhance the legal power of the recipient by writing a document in addition to transferring the gift itself.

איתמר רב יהודה אמר שמואל, הלכה: כותבין ונותנין. וכן אמר רבא אמר רב נחמן, הלכה: כותבין ונותנין.

It was stated that Rav Yehuda says that Shmuel says that the halakha is that one writes a document and gives the money in this case. And Rava says similarly that Rav Naḥman says that the halakha is that one writes a document and gives the money in this case.

מתני׳ הכותב נכסיו לבניו, צריך שיכתוב ״מהיום ולאחר מיתה״, דברי רבי יהודה. רבי יוסי אומר: אינו צריך.

Mishnah: A healthy person who writes a document granting his property to his sons in his lifetime, but wishes to continue to derive benefit from it until his death, must write: I give the property from today and after my death. This is the statement of R' Yehuda. R' Yosei says: He need not write: From today and after my death; it is sufficient for him to write that the transfer will take effect after he dies.

הכותב נכסיו לבנו לאחר מותו ⁠– האב אינו יכול למכור, מפני שהן כתובין לבן; והבן אינו יכול למכור, מפני שהן ברשות האב.

If one writes a document granting his property to his son from today and after his death, the father cannot sell the property because it is written as granted to the son, and the son cannot sell it because it is still in the possession of the father with regard to using the property and consuming its produce.