D&C 102

It is in this section that the Lord organizes the high council. A body of High Priest to -

"...appointed to speak before the council are to present the case, after the evidence is examined, in its true light before the council; and every man is to speak according to equity and justice." (Doctrine and Covenants | Section 102:16)

And they are to speak according to equity and justice and -

"...act in that office according to the law of heaven..." (Doctrine and Covenants | Section 102:4)

In the previous section of the Doctrine and Covenants, in parable, the Lord taught that He planted in His vineyard, twelve olive trees. It was the watchmen's responsibility to watch and protect the vineyard from the enemy. I percieve these trees to be the Quorum of the Twelve Apostles from which comes the "law of heaven". The high council are watchmen to protect the vineyard with equity and justice according to the law of heaven. As the prophet was preparing to organize the first high council, he wrote -

"At a council of the High Priests and Elders, (Orson Hyde, clerk,) at my house in Kirtland, on the evening of the 12th of February, I remarked that I should endeavor to set before the council the dignity of the office which had been conferred on me by the ministering of the angel of God, by His own voice, and by the voice of this Church; that I had never set before any council in all the order in which it ought to be conducted, which, perhaps, has deprived the councils of some or many blessings.

And I continued and said, no man is capable of judging a matter, in council, unless his own heart is pure; and that we are frequently so filled with prejudice, or have a beam in our own eye, that we are not capable of passing right decisions.

Our acts are recorded, and at a future day they will be laid before us, and if we should fail to judge right and injure our fellow-beings, they may there, perhaps, condemn us; there they are of great consequence, and to me the consequence appears to be of force, beyond anything which I am able to express. Ask yourselves, brethren, how much you have exercised yourselves in prayer since you heard of this council; and if you are now prepared to sit in council upon the soul of your brother." (Joseph Smith, HC 2:25-26, 31.)