Acts 1:24

and praying, they said: Thou, Lord, who knowest the hearts of all, make known which of these two thou hast chosen,

Acts 15:8

And God, who knows the heart, became a witness for them, by giving them the Holy Spirit, as he gave it also to us;

Acts 6:6

whom they set before the apostles. And when they had prayed, they laid their hands on them.

Revelation 2:23

And I will kill her children with death; and all the churches shall know that I am he that searches the reins and the hearts: and I will give to every one of you according to your works.

Luke 6:12-13

And it came to pass in those days, that he went out into the mountain to pray; and he spent the night in prayer to God.

John 2:24-25

But Jesus did not trust himself to them, because he knew all men,

John 21:17

He said to him a third time: Simon, son of Jonah, do you love me? Peter was grieved because he said to him the third time, Do you love me? And he said to him: Lord, thou knowest all things, thou knowest that I love thee. Jesus said to him: Feed my sheep.

Acts 13:2-3

And while they were ministering to the Lord, and fasting, the Holy Spirit said: Set apart for me Barnabas and Saul, to the work to which I have called them.

Acts 14:23

And when they had appointed elders for them in every church, with prayer and fasting, they commended them to the Lord, on whom they believed.

Romans 8:27

And he that searches the hearts knows what is the mind of the Spirit, that he intercedes for the saints according to the will of God.

Hebrews 4:13

And there is no creature which is not manifest in his sight: but all things are naked, and exposed to the eyes of him to whom we must give an ac count.

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
And while they were ministering to the Lord, and fasting, the Holy Spirit said: Set apart for me Barnabas and Saul, to the work to which I have called them.
Luke 6:12
And it came to pass in those days, that he went out into the mountain to pray; and he spent the night in prayer to God.

Thou, lord

Acts 15:8
And God, who knows the heart, became a witness for them, by giving them the Holy Spirit, as he gave it also to us;
John 2:24
But Jesus did not trust himself to them, because he knew all men,
John 21:17
He said to him a third time: Simon, son of Jonah, do you love me? Peter was grieved because he said to him the third time, Do you love me? And he said to him: Lord, thou knowest all things, thou knowest that I love thee. Jesus said to him: Feed my sheep.
Hebrews 4:13
And there is no creature which is not manifest in his sight: but all things are naked, and exposed to the eyes of him to whom we must give an ac count.
Revelation 2:23
And I will kill her children with death; and all the churches shall know that I am he that searches the reins and the hearts: and I will give to every one of you according to your works.