Counsel
Isaiah saw the coming king as one whom the Spirit of the Lord had supplied with counsel (Isa 11:2); he was to be called “Counselor.” The counsel of peace was to be established between the coming Messiah and the high priest (Zech 6:13). Prophets were spoken of as standing “in the council of the Lord to hear his word.”
In the NT Joseph of Arimathea was called a bouleutēs, a respected member of the council (Mark 15:43; Luke 23:50). “Counsel” was used less in the NT than the OT, and most frequently was the equivalent of advice. It was said, however, that God’s counsel was immutable (Heb 6:17). The counsel of man was perfectly open to God (1 Cor 4:4). No human counsel could be hidden from God, but His counsel was above the figuring out by men (Rom 11:33).
International Standard Bible Encyclopedia (1915)
koun’-sel, koun’-seler (sumboulion): Ordinarily found as object of verb "to take" or "to give," expressing, beside the idea of a practical end to be reached, that of consultation and deliberation among those united in a common cause (Mt 12:14; Mr 3:6). A counselor (sumboulos) is a confidential adviser (Ro 11:34); often in the Old Testament (Isa 9:6; Pr 24:6, etc.). Confounded in the King James Version with "councillor" (see above), the latter being an official adviser, which the former does not necessarily mean.