Exodus 17: 8-13
Moses prays for the newly liberated Hebrews in their military engagement but when he can no longer hold out his arms in supplication Aaron and Hur support them and the battle is won.

2 Timothy 3: 14 - 4.2
Paul reminds Timothy to be true to his teachers (among whom was Paul), to what he has been taught, to the scriptures, and to take every opportunity to proclaim the word of God

Luke 18: 1-8
The widow seeks justice from a judge who is unconcerned and gives no answer.  Her persistence finally wins through.  By contrast, God will always see justice done to those who cry out.