One of the most important duties of the Notary is to administer oaths and affirmations, which are solemn promises of truthfulness made by a signer, witness, or new office-holder.
An oath is a promise to a deity and an affirmation is a pledge on one's personal honor. Both are legally binding promises to tell the truth and subject the oath-taker or affirmant to penalties for perjury.
Verbal oaths or affirmations may be notarial acts in their own right -- as when "swearing in" a new public official -- or they may be part of performing a jurat notarization for a signed document.
It is customary for the Notary to ask the oath-taker or affirmant to raise the right hand in a pledging gesture or to place it over one's heart. Oaths and affirmations should be always be taken seriously by the Notary and the person being sworn or affirmed.