1 Samuel 1:12
It happened, as she continued praying before Yahweh, that Eli saw her mouth.
Luke 11:8-10
I tell you, although he will not rise and give it to him because he is his friend, yet because of his persistence, he will get up and give him as many as he needs.
Luke 18:1
He also spoke a parable to them that they must always pray, and not give up,
Ephesians 6:18
with all prayer and requests, praying at all times in the Spirit, and being watchful to this end in all perseverance and requests for all the saints:
Colossians 4:2
Continue steadfastly in prayer, watching therein with thanksgiving;
1 Thessalonians 5:17
Pray without ceasing.
James 5:16
Confess your offenses to one another, and pray for one another, that you may be healed. The insistent prayer of a righteous person is powerfully effective.