Responsa for Bava Batra 227:3

אמר רב יוסף כוותי דידי מסתברא דאמר רב יהודה שלשה שנכנסו לבקר את החולה רצו כותבין רצו עושין דין ואי סלקא דעתך כל זמן שיושבין ליחוש דלמא הדר ביה

Three [persons] who came to visit a sick man may, if they wish, [either] write down [his instructions with reference to the disposal of his estate, or], if they prefer it, give judgment.<span class="x" onmousemove="('comment',' V. p. 469, n. 16 supra. ');">¹⁰</span> Now, if it is assumed<span class="x" onmousemove="('comment',' Lit., 'if it enters your mind'. ');">¹¹</span> [that the testator may withdraw] during the whole time the session is in progress, [how can they give judgment?<span class="x" onmousemove="('comment',' Which has the power to make the testator's instructions legally and irrevocably binding at once. ');">¹²</span> Surely it may he apprehended that he might withdraw!<span class="x" onmousemove="('comment',' Before the session was over, the testator might change his mind, and thus annul all the work of the court. ');">¹³</span> — R. Ashi said: Discussing this tradition in the presence of R. Kahana, [I argued:] Is this<span class="x" onmousemove="('comment',' The statement of Rab Judah which R. Joseph quoted in support of his view. ');">¹⁴</span>

Teshuvot Maharam