Reference for Bava Batra 302:1
וכי קיימא הות הדרא בה זימנא חדא חלשא שלחה ליה תא קני שלח לא בעינא שלחה ליה תא קני כל היכא דבעית אזל שיירה וקנו מינה כי קיימא הדרא בה
but as [soon as] she recovered she withdrew. On one occasion she fell ill and sent [word] to him, 'Come [and] take possession'. He replied,<span class="x" onmousemove="('comment',' Lit., 'sent'. ');"><sup>1</sup></span> 'I have no desire'. [Thereupon] she [again] sent [word] to him, 'Come [and] take possession in whatever manner you desire'.<span class="x" onmousemove="('comment',' So that she shall not be able again to retract. ');"><sup>2</sup></span> [Then] he went, left for her [some portion of the intended gift]<span class="x" onmousemove="('comment',' In such a case the donor cannot withdraw, (Cf. our Mishnah, supra 146b.) ');"><sup>3</sup></span>