What is the ruling on sitting on a chair during teaching?

The questioner : If you would allow me, once the Shaykh Abu Malik was brought a chair to sit on during the lesson, he refused. He spoke at length and cited the hadith of the Prophet (peace and blessings be upon him): "The Prophet (peace and blessings be upon him) forbade al-ithrah (seeking distinction)." He said that this leads to hatred, resentment, and dislike, meaning this is considered al-ithrah?

The Shaykh : No, this is not of that category. Why doesn't he go up on the minbar? Sitting on a chair is to appear before the teachers, I mean, before the students.