The word(s) "lesson" appears 168 time(s) in 166 verse(s) in Quran in Mohsin Khan translation.

(161) And those who believe in (the Oneness of) Allah and His Messengers - they are the Siddiqun (i.e. those followers of the Prophets who were first and foremost to believe in them), and the martyrs with their Lord, they shall have their reward and their light. But those who disbelieve (in the Oneness of Allah - Islamic Monotheism) and deny Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) - they shall be the dwellers of the blazing Fire.

(162) Verily, those who oppose Allah and His Messenger (Muhammad صلى الله عليه وسلم) will be disgraced, as those before them (among the past nation) were disgraced. And We have sent down clear Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.). And for the disbelievers is a disgracing torment.

(163) But those who disbelieved (in the Oneness of Allah - Islamic Monotheism) and denied Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), they will be the dwellers of the Fire, to dwell therein forever. And worst indeed is that destination .

(164) Nay! Verily, he has been opposing Our Ayat (proofs, evidence, verses, lessons, signs, revelations).

(165) But they belied Our Ayat (proofs, evidence, verses, lessons, signs, revelations, and that which Our Prophet صلى الله عليه وسلم brought) completely.

(166) But those who disbelieved in Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), they are those on the Left Hand (the dwellers of Hell).