The Hebrew noun sod (סוֹד) refers to a council, an inner circle of intimate associates, a secret counsel, or the confidential sharing between trusted friends. It appears about 21 times in the Old Testament. The word captures the idea of privileged access to private deliberation — being 'in' on what is being planned.
The theological depth of sod is extraordinary. The prophets understood themselves as having been admitted to the heavenly council — the sod of Yahweh — where divine decrees are issued and heavenly messengers dispatched (Amos 3:7; Jeremiah 23:18). Psalm 25:14 declares that the sod (intimate counsel) of the LORD belongs to those who fear him. This is not mere information transfer but relational intimacy — the holy God inviting his covenant people into his confidence. The New Testament develops this theme in John 15:15 where Jesus calls his disciples friends, not servants, because he has told them everything he heard from the Father.