'Brethren' in the Bible

On the left hand were their kinsmen the sons of Merari: Ethan the son of Kishi, the son of Abdi, the son of Malluch,

Their kinsmen the Levites were appointed for all the service of the tabernacle of the house of God.

Then King David rose to his feet and said, “Listen to me, my brethren and my people; I had intended to build a permanent home for the ark of the covenant of the Lord and for the footstool of our God. So I had made preparations to build it.