Luke 18:1

Jesus propos'd likewise this parable to them, to show that they should persevere in prayer, and not be discouraged.

Philippians 4:6

the Lord is coming: be not in any manner of sollicitude, but in all your occasions lay your requests before God by prayer and supplication accompany'd by thanksgiving.

Colossians 4:2

Persevere and be vigilant in prayer and in thanksgiving:

Treasury of Scripture Knowledge

Summary

Because he hath inclined his ear unto me, therefore will I call upon him as long as I live.

Bible References

Therefore

Luke 18:1
Jesus propos'd likewise this parable to them, to show that they should persevere in prayer, and not be discouraged.
Philippians 4:6
the Lord is coming: be not in any manner of sollicitude, but in all your occasions lay your requests before God by prayer and supplication accompany'd by thanksgiving.
Colossians 4:2
Persevere and be vigilant in prayer and in thanksgiving: