In preliterate cultures very little is written down. For example in Jesus’ day, covenants were formally entered into (or canceled) by agreeing out loud three times in the presence of witnesses. This pattern of triple assent shows up repeatedly in the Bible.
Young Samuel ‘contracts’ to serve the LORD:
“…the LORD called, “Samuel! Samuel!” and he said, “Here I am!” and ran to Eli, and said, “Here I am, for you called me.” But he said, “I did not call; lie down again.” And the LORD called again, “Samuel!” And Samuel arose and went to Eli, and said, “Here I am, for you called me.” But he said, “I did not call, my son; lie down again.” And the LORD called Samuel again the third time. And he arose and went to Eli, and said, “Here I am, for you called me.”
Young Elisha agrees to “take up the mantle” of Elijah:
“Now when the LORD was about to take Elijah up to heaven by a whirlwind…Elijah said to Elisha, “Tarry here, I pray you; for the LORD has sent me as far as Bethel.” But Elisha said, “As the LORD lives, and as you yourself live, I will not leave you.” So they went down to Bethel. Elijah said to him, “Elisha, tarry here, I pray you; for the LORD has sent me to Jericho.” But he said, “I will not leave you.” So they came to Jericho. …Then Elijah said to him, “Tarry here, I pray you; for the LORD has sent me to the Jordan.” But he said, “I will not leave you.”
“Now Peter was sitting outside in the courtyard. And a maid came up to him, and said, “You also were with Jesus the Galilean.” But he denied it before them all, saying, “I do not know what you mean.” And when he went out to the porch, another maid [said], “This man was with Jesus of Nazareth.” And again he denied it with an oath, “I do not know the man.” After a little while the bystanders came up and said to Peter, “Certainly you are also one of them, for your accent betrays you.” Then he began to invoke a curse on himself and to swear, “I do not know the man.” And immediately the cock crowed. And Peter remembered the saying of Jesus, “Before the cock crows, you will deny me three times.”But after the Resurrection, and before the Ascension, Jesus re-established his covenant with Peter: