The door keeper

Psalm 84:8–12 “O Yahweh, God of hosts, hear my prayer; give ear, O God of Jacob. Selah Look at our shield, O God, and have regard for the face of your anointed one. Because better is a day in your courtyards than a thousand elsewhere. I would rather be at the threshold of the house of my God than to dwell in the tents of wickedness. Because Yahweh God is a sun and a shield; Yahweh gives grace and honor. He does not withhold good from those who walk blamelessly. O Yahweh of hosts, blessed is the man who trusts you.”

Holman Illustrated Bible Dictionary (Doorkeeper)

DOORKEEPER Person guarding access to an important or restricted place. Temple doorkeeper was an important office in biblical times. The doorkeepers collected money from the people (2 Kings 22:4). Some Levites were designated doorkeepers (or “gatekeepers”) for the ark (1 Chron. 15:23–24). The Persian kings used eunuchs for doorkeepers (Esther 2:21). Women also served this function (John 18:16–17; Acts 12:13).

The Hebrew word underlying the translation “doorkeeper” in Ps. 84:10 (KJV, RSV, NIV) appears only once in the OT. The root idea is threshold. Thus some translations (NASB, REB, TEV) render the word “at the threshold” or some similar expression. The reference is to those waiting outside the temple either to beg alms or to seek admission. The thought of the verse is that it is better to be standing outside the temple than to be inside the tents of the wicked.

For a king of Israel there were three things that proved God was with him, proved that God called him:

The anointing - David and Samuel

The testing - cutting of Saul’s garment, not every opportunity is the will of God. The testing typically will involve you with your authority, your compatriot and those you lead.

The passing of the test - David could have killed Saul