Acts 1:24

And they offered this prayer--"O Lord, who reads all hearts, show which of these two men you have chosen

Acts 15:8

Now God, who reads all hearts, declared his acceptance of the Gentiles, by giving them the Holy Spirit, just as he did to us.

Acts 6:6

And they brought these men to the Apostles, who, after praying, placed their hands on them.

Revelation 2:23

I will also put her children to death; and all the Churches shall learn that I am he who 'looks into the hearts and souls of men'; and I will give to each one of you what his life deserves.

Luke 6:12-13

Now about that time, Jesus went out, up the hill, to pray, and spent the whole night in prayer to God.

John 2:24-25

But Jesus did not trust himself to them, since he could read every heart,

John 21:17

The third time, Jesus said to him: "Simon, son of John, are you my friend?" Peter was hurt at his third question being 'Are you my friend?'; and exclaimed: "Master, you know everything! You can tell that I am your friend." "Feed my sheep," said Jesus.

Acts 13:2-3

While they were engaged in the worship of the Lord and were fasting, the Holy Spirit said: "Set apart for me Barnabas and Saul, for the work to which I have called them."

Acts 14:23

They also appointed Officers for them in every Church, and, after prayer and fasting, commended them to the Lord in whom they had learned to believe.

Romans 8:27

Yet he who searches all our hearts knows what the Spirit's meaning is, because the pleadings of the Spirit for Christ's People are in accordance with his will.

Hebrews 4:13

There is no created thing that can hide itself from the sight of God. Everything is exposed and laid bare before the eyes of him to whom we have to give account.

Treasury of Scripture Knowledge

Summary

And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen,

Bible References

They

Acts 13:2
While they were engaged in the worship of the Lord and were fasting, the Holy Spirit said: "Set apart for me Barnabas and Saul, for the work to which I have called them."
Luke 6:12
Now about that time, Jesus went out, up the hill, to pray, and spent the whole night in prayer to God.

Thou, lord

Acts 15:8
Now God, who reads all hearts, declared his acceptance of the Gentiles, by giving them the Holy Spirit, just as he did to us.
John 2:24
But Jesus did not trust himself to them, since he could read every heart,
John 21:17
The third time, Jesus said to him: "Simon, son of John, are you my friend?" Peter was hurt at his third question being 'Are you my friend?'; and exclaimed: "Master, you know everything! You can tell that I am your friend." "Feed my sheep," said Jesus.
Hebrews 4:13
There is no created thing that can hide itself from the sight of God. Everything is exposed and laid bare before the eyes of him to whom we have to give account.
Revelation 2:23
I will also put her children to death; and all the Churches shall learn that I am he who 'looks into the hearts and souls of men'; and I will give to each one of you what his life deserves.