Simplify the following text for a Grade 5 native English-speaking person.
Original: An oath ( from Anglo-Saxon Ä Ã , also called plight ) is either a statement of fact or a promise calling upon something or someone that the oath maker considers sacred , usually God , as a witness to the binding nature of the promise or the truth of the statement of fact .
Simplified: An oath ( from Anglo-Saxon Ä Ã ) is a promise .