Luke 2:37
and then being a widow of eighty-four years. She was never absent from the Temple, but worshipped, by day and by night, with fasting and prayer.
Luke 11:8-13
"I tell you that even if he will not rise and give him the loaves because he is his friend, at any rate because of his persistency he will rouse himself and give him as many as he requires.
Luke 18:7
And will not God avenge the wrongs of His own People who cry aloud to Him day and night, although He seems slow in taking action on their behalf?
Ephesians 6:18
Pray with unceasing prayer and entreaty on every fitting occasion in the Spirit, and be always on the alert to seize opportunities for doing so, with unwearied persistence and entreaty on behalf of all God's people,