Acts 1:24

And the brethren prayed, saying, "Thou, Lord, who knowest the hearts of all, show clearly which of these two Thou hast chosen

Acts 15:8

And God, who knows all hearts, gave His testimony in their favour by bestowing the Holy Spirit on them just as He did on us;

Acts 6:6

These men they brought to the Apostles, and, after prayer, they laid their hands upon them.

Revelation 2:23

Her children too shall surely die; and all the Churches shall come to know that I am He who searches into men's inmost thoughts; and to each of you I will give a requital which shall be in accordance with what your conduct has been.

Luke 6:12-13

About that time He went out on one occasion into the hill country to pray; and He remained all night in prayer to God.

John 2:24-25

But for His part, Jesus did not trust Himself to them, because He knew them all,

John 21:17

A third time Jesus put the question: "Simon, son of John, am I dear to you?" It grieved Peter that Jesus asked him the third time, "Am I dear to you?" "Master," he replied, "you know everything, you can see that you are dear to me." "Then feed my much-loved sheep," said Jesus.

Acts 13:2-3

While they were worshipping the Lord and fasting, the Holy Spirit said, "Set apart for Me, now at once, Barnabas and Saul, for the work to which I have called them."

Acts 14:23

And in every Church, after prayer and fasting, they selected Elders by show of hands, and commended them to the Lord on whom their faith rested.

Romans 8:27

and the Searcher of hearts knows what the Spirit's meaning is, because His intercessions for God's people are in harmony with God's will.

Hebrews 4:13

And no created thing is able to escape its scrutiny; but everything lies bare and completely exposed before the eyes of Him with whom we have to do.

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 worshipping the Lord and fasting, the Holy Spirit said, "Set apart for Me, now at once, Barnabas and Saul, for the work to which I have called them."
Luke 6:12
About that time He went out on one occasion into the hill country to pray; and He remained all night in prayer to God.

Thou, lord

Acts 15:8
And God, who knows all hearts, gave His testimony in their favour by bestowing the Holy Spirit on them just as He did on us;
John 2:24
But for His part, Jesus did not trust Himself to them, because He knew them all,
John 21:17
A third time Jesus put the question: "Simon, son of John, am I dear to you?" It grieved Peter that Jesus asked him the third time, "Am I dear to you?" "Master," he replied, "you know everything, you can see that you are dear to me." "Then feed my much-loved sheep," said Jesus.
Hebrews 4:13
And no created thing is able to escape its scrutiny; but everything lies bare and completely exposed before the eyes of Him with whom we have to do.
Revelation 2:23
Her children too shall surely die; and all the Churches shall come to know that I am He who searches into men's inmost thoughts; and to each of you I will give a requital which shall be in accordance with what your conduct has been.