the mind > language > speech > agreement > promise > promise, vow, or pledge [verb (intransitive)] > give assurances (3)
transitive. To guarantee. absol. or with subordinate clause. To give a guarantee, promise, pledge oneself. Obsolete.
intransitive. To give assurance, guarantee, vouch.
A pledge, a formal declaration, a solemn promise; esp. in to give (one's) faith. See also phrases 2b. Now rare and archaic.