Luke 6:12

And it happened during that time that Jesus went out to the mountain [i.e., probably a hillside near Capernaum] to pray, and continued praying to God all night.

Mark 1:35

Very early in the morning, [even] before daylight, Jesus woke up, left Simon's house [verse 29] and went out to a deserted place where He prayed.

Matthew 6:6

But when you pray, go to a private place and after closing the door, pray to your Father who is in a secret place, and [since] He sees in secret places, He will reward you.

Matthew 14:23-25

After He had dispersed them, He went up into the mountain by Himself to pray. When evening had come He was there alone.

Mark 6:46

And after He had left them He went into a mountain to pray.

Mark 14:34-36

He said to them, "My soul is extremely grieved, even to the point where I could die. Stay here and be alert [i.e., in prayer]."

Colossians 4:2

Continue to pray regularly; stay alert and be thankful.

Hebrews 5:7

During His life on earth Jesus offered up prayers and special requests with loud crying and tears to God, who was able to save Him from dying, and He was heard because of His [earnest] devotion [to God].

Treasury of Scripture Knowledge

Summary

And it came to pass in those days, that he went out into a mountain to pray, and continued all night in prayer to God.

Bible References

Continued

Matthew 14:23
After He had dispersed them, He went up into the mountain by Himself to pray. When evening had come He was there alone.
Mark 6:46
And after He had left them He went into a mountain to pray.
Colossians 4:2
Continue to pray regularly; stay alert and be thankful.

General references

Mark 1:35
Very early in the morning, [even] before daylight, Jesus woke up, left Simon's house [verse 29] and went out to a deserted place where He prayed.
Mark 3:13
He then went up into the mountain and summoned those He wanted to come to Him and they came.
Mark 6:46
And after He had left them He went into a mountain to pray.
Luke 5:16
So, He went away to deserted places and prayed.
John 6:3
Then Jesus went up to a high plateau [Note: This place, northeast of Lake Galilee, is called "The Golan Heights," today] and sat down there with His disciples.