2 verses have
brethren
in Edition Clear Qur'an by Talal Itani / Al-Ahzaab (The Clans)

33:5Call them after their fathers; that is more equitable with God. But if you do not know their fathers, then your brethren in faith and your friends. There is no blame on you if you err therein, barring what your hearts premeditates. God is Forgiving and Merciful.

33:18God already knows the hinderers among you, and those who say to their brethren, “Come and join us.” Rarely do they mobilize for battle.