The Zadok priests are the children/sons of light.
Verses where they refer to themselves as the “sons of light.”
The Community Rule
Begins on Page 134
He shall admit into the Covenant of Grace all those who have freely devoted themselves to the observance of God’s precepts, that they may be joined to the counsel of God and may live perfectly before Him in accordance with all that has been revealed concerning their appointed times, and that they may love all the sons of light, each according to his lot in God’s design, and hate all the sons of darkness, [10] each according to his guilt in God’s vengeance.
He shall be cut oʃ from the midst of all the sons of light, and because he has turned aside from God on account of his idols and his stumbling-block of sin, his lot shall be among those who are cursed for ever.’
The Master shall instruct all the sons of light and shall teach them the nature of all the children of men according to the kind of spirit which they possess, the signs identifying their works during their lifetime, their visitation for chastisement, and the time of their reward.
Master refers to an elder.