For example, if one swears, "I will give something to so-and-so," or "I will not give it to him," or "I swear that I gave it to him," or "I swear that I did not give it to him," this is an oath about others.
If he said, "I swear that I will sleep" or "that I will not sleep," "I slept" or "I did not sleep" - these are oaths concerning intangible matters.
If one said, "I swear that I will throw a pebble into the sea," or "I will not throw the pebble," "I threw the pebble," or "I did not throw," - these are oaths concerning non-beneficial acts.
Art: A Woman Asleep at Table - Jan Vermeer Van Delft