It's a term in the scriptures.
One example:
(Numbers 3:9) 9 You are to give the Levites to Aaron and his sons. They are given ones, given to him from the Israelites.
More info about:
*** w92 4/15 pp. 16-17 par. 21 Jehovah’s Provision, the “Given Ones” ***
21 The Nethinim’s added privileges were linked directly to spiritual activities. The sons of the servants of Solomon evidently received administrative responsibilities. Similarly today, Jehovah has blessed his people with “gifts in men” to care for their needs. (Ephesians 4:8, 11, 12) Included in this provision are many hundreds of mature, experienced brothers who share in ‘shepherding the flocks,’ serving as circuit and district overseers and on Branch Committees at the Watch Tower Society’s 98 branches. (Isaiah 61:5) At the world headquarters of the Society, under the direction of “the faithful steward” and its Governing Body, capable men receive training to help in preparing spiritual food supplies. (Luke 12:42) Other longtime dedicated volunteers have been trained to operate Bethel homes and factories and to oversee programs worldwide in constructing new branch facilities and halls for Christian worship. They have excelled in serving as close helpers of the anointed remnant, who constitute part of the royal priesthood.—Compare 1 Corinthians 4:17; 14:40; 1 Peter 2:9.