"There are church members who have been quick to catch up unkind suppositions and to speak disparagingly of the teacher before other church members and even in the presence of the children. Some have talked freely and bitterly concerning a teacher without clearly understanding the difficulty of which they were speaking. This should not be. The one who thinks that a teacher has done wrong should follow the directions given in the word: “If thy brother shall trespass against thee, go and tell him his fault between thee and him alone.” Matthew 18:15 . Until this has been done, no one is justified in telling others of a brother's mistakes. CT 154.1"
"Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother."
The EGW passage directly quotes Matthew 18:15 and applies it to the situation of addressing concerns about a teacher's actions.
"Parents, when the church-school teacher tries so to train and discipline your children that they may gain eternal life, do not in their presence criticize his actions, even though you may think him too severe. If you desire them to give their hearts to the Saviour, co-operate with the teacher's efforts for their salvation. How much better it is for children, instead of hearing criticism, to hear from the lips of their mother words of commendation regarding the work of the teacher. Such words make lasting impressions and influence the children to respect the teacher. CT 154.2"
"And, ye fathers, provoke not your children to wrath: but bring them up in the nurture and admonition of the Lord."
Both passages address the importance of parents' role in the upbringing of their children. Ephesians 6:4 warns against provoking children to wrath, while the EGW passage advises parents to support the teacher's efforts and avoid criticizing them in front of the children, which aligns with the principle of not provoking them.