Reference for Kiddushin 53:4

שמע מינה לא בעינן צבורים בה שאני שטר דאפסירא דארעא הוא

[But if he stipulates,] 'on condition that you indite a deed for him,' he can retract from both the deed and the field.<span class="x" onmousemove="('comment',' For they are interdependent.');">⁸</span> R'Hiyya B'Abin said in R'Huna's name: There are three [kinds of] deeds. Two, as just stated.

Jastrow