פירוש על קידושין 118:19

If Shmuel had said “the halakhah agrees with Rabbi” I might have thought that only in that case do we interpret his statement as a stipulation because he cannot be saying “Be divorced after my death.” People know that one cannot divorce after death. But when it comes to kiddushin, they can take place after thirty days. So maybe in that case the man was retracting his earlier statement.