Asseveration

[…] no man is believ’d a jot the more for all the Aſſeverations, Damnings and Swearings he makes: […]

Source: wiktionary

Custom-houſe oaths and political oaths are but little regarded even by ſome who pretend to principles of honeſty and religion: and a Quaker’s aſſeveration is with us juſtly put upon the ſame footing with the oath of any other perſon.

Source: wiktionary

[…] on all such occasions Mr. Grimwig plants, fishes, and carpenters with great ardour, doing everything in a very singular and unprecedented manner; but always maintaining, with his favourite asseveration, that his mode is the right one.

Source: wiktionary

The true oath consists in the simple asseveration, uttered in perfect consciousness and under a sense of the presence of God, before Him, and in Him.

Source: wiktionary