Deuteronomy 19:18

and the judges shall make diligent inquisition, - and lo! if the witness be, a false witness and, falsely, have answered against his brother,

Deuteronomy 13:14

and thou shalt enquire, and search out, and ask diligently, - and lo! true - certain, is the thing, this abomination, hath been done, in thy midst,

Deuteronomy 17:4

and it shall be told thee and thou shalt hear, - and shalt enquire diligently, and lo! true - certain, is the report, this abominable thing hath been done in Israel,

2 Chronicles 19:6-7

and said unto the judges, See what, ye, are doing, inasmuch as, not for man, must ye judge, but for Yahweh, - who will be with you, in the word of justice.

Job 19:16

To mine own servant, I called, and he would not answer, With mine own mouth, I kept entreating him;

Treasury of Scripture Knowledge

Summary

And the judges shall make diligent inquisition: and, behold, if the witness be a false witness, and hath testified falsely against his brother;

Bible References

Diligent

Deuteronomy 13:14
and thou shalt enquire, and search out, and ask diligently, - and lo! true - certain, is the thing, this abomination, hath been done, in thy midst,
Deuteronomy 17:4
and it shall be told thee and thou shalt hear, - and shalt enquire diligently, and lo! true - certain, is the report, this abominable thing hath been done in Israel,
2 Chronicles 19:6
and said unto the judges, See what, ye, are doing, inasmuch as, not for man, must ye judge, but for Yahweh, - who will be with you, in the word of justice.
Job 19:16
To mine own servant, I called, and he would not answer, With mine own mouth, I kept entreating him;

General references

Deuteronomy 5:20
Neither shalt thou testify against thy neighbour with a witness of falsehood:
Deuteronomy 25:1
When there ariseth a controversy between men, and they come nigh unto judgment, and judgment is granted them, then shall they justify the righteous man, and condemn the lawless.
John 7:51
Surely, our law, doth not judge the man, unless it hear first from him, and get to know what he is doing?