2,653. Oaths Without Actions
Hilchos Shevuos 4:20
Let’s say that someone takes an oath to eat a certain loaf on that same day but the day passes without him eating it. If he acted unintentionally, he must bring a variable guilt offering; if he acted intentionally, he is exempt from lashes because, despite taking a false oath, he performed no action.
Hilchos Shevuos 4:21
One who took an oath that he ate something is liable to the penalty of lashes if he didn’t actually eat it and one who took an oath that he didn’t eat is liable to lashes if he did. This is so even though he performed no action because it was a false oath at the time he made it. However, if one takes an oath to perform a certain action, it isn’t a false oath when it’s made.