Is a teacher's raising of his voice and getting angry at students to discipline them considered excessive and forbidden discipline, or is it from the guidance of the Righteous Predecessors? And is it permissible for a student to leave a strict teacher, or is patience obligatory upon him?

The fundamental principle in teaching is gentleness, which is the guidance of the Prophet, peace and blessings be upon him, as stated in the Hadith of Mu'awiyah ibn al-Hakam al-Sulami, may Allah be pleased with him. However, a teacher may sometimes use strictness in specific situations, as the Prophet, peace and blessings be upon him, did when he removed a gold ring from a man's hand. Raising one's voice is not forbidden if it does not result in harm, but it is an excess that should be avoided. A teacher should be patient with his students, and students should be patient with their teacher and benefit from his knowledge.