Matthew 6:6 NIV

2 Kings 4:33 NIV
He went in, shut the door on the two of them and prayed to the Lord.

Acts 9:40 NIV
Peter sent them all out of the room; then he got down on his knees and prayed. Turning toward the dead woman, he said, “Tabitha, get up.” She opened her eyes, and seeing Peter she sat up.

Isaiah 26:20 NIV
Go, my people, enter your rooms and shut the doors behind you; hide yourselves for a little while until his wrath has passed by.

Isaiah 65:24 NIV
Before they call I will answer; while they are still speaking I will hear.

Matthew 14:23 NIV
After he had dismissed them, he went up on a mountainside by himself to pray. Later that night, he was there alone,

Matthew 26:36-39 NIV
Then Jesus went with his disciples to a place called Gethsemane, and he said to them, “Sit here while I go over there and pray.” He took Peter and the two sons of Zebedee along with him, and he began to be sorrowful and troubled. Then he said to them, “My soul is overwhelmed with sorrow to the point of death. Stay here and keep watch with me.” Going a little farther, he fell with his face to the ground and prayed, “My Father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will.”

Matthew 6:18 NIV
so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.