One who sells a loan can still pardon the debt.
If a man must pay a creditor and a Kesuvah but only has enough to pay one who gets paid?
If a creditor demands to be paid money and the borrower only has land, we force him to sell his land.
One refuses to do an עשה what is done?
If her husband gave her Get and said 'you are not divorced until 30 days from now' and she left the Get in צידי רשות הרבים is she divorced?
רבי אליעזר one can make his wife swear even about household expenses.