Makkot 15 - Uncertain Warning
In order for lashes to be administered, the transgressor must be warned shortly before. In the cases where such warning cannot be stated with certainty, is the court still allowed to administer lashes?
For example, one proclaims, "An oath that I will eat this loaf today!" If he is warned in the morning that he better eat the loaf, or else he will receive lashes, this is an uncertain warning, because he may still eat the loaf later on. This applies throughout the day: he cannot be told with certainty that if does not eat the loaf now he will incur lashes, since he can eat it a while later. Potentially, he could be warned on the very last moment of a day, but practically it is impossible. In this situation, Rabbi Yochanan says that an uncertain warning is a legal warning; however, he does not receive lashes because he does no action. On the contrary, Resh Lakish does allow lashes even for no action, but Resh Lakish considers uncertain warning invalid. Thus, according to both, he does not receive lashes, but for different reasons.
Jacobus Vrel - Street Scene with Bakery