文殊三教授

I recall the Lecturer had highlighted why these 3 Teachings were so important.
The Teachings were given personally to Master Tsongkhapa by Manjushri Bodhisattva himself.

文殊菩薩親自指導了宗喀巴大師三大修行原則：
一、將上師與本尊視為毫無差別而作祈禱。
二、研閱沒有過失、可靠可信的經論。
三、用種種方式淨除罪障，累積資糧。
人稱｢文殊三教授｣。
reference: ［福智金鬘．師承］《 無數修持 》 拉卜楞寺．至尊大小阿克師徒 ⑪ - 一代宗師［福智接班．真如本性］