Isaac’s endurance was based on faith in God’s promise, faith that was instilled in him by his aged parents and later reinforced by Jehovah’s own word to him.
Iisak pidas vastu tänu usule Jumala tõotusesse, usule, mille olid temasse juurutanud eakad vanemad ning mida hiljem kinnitas Jehoova ise oma sõnadega.