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

(11) There has already been a sign for you (O Jews) in the two armies that met (in combat i.e. the battle of Badr). One was fighting in the Cause of Allah, and as for the other, (they) were disbelievers. They (the believers) saw them (the disbelievers) with their own eyes twice their number (although they were thrice their number). And Allah supports with His Victory whom He wills. Verily, in this is a lesson for those who understand. (See Verse 8:44). (Tafsir At-Tabari)

(12) Verily! Those who disbelieve in the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of Allah and kill the Prophets without right, and kill those men who order just dealings, ... then announce to them a painful torment.

(13) Say: "O people of the Scripture (Jews and Christians)! Why do you reject the Ayat of Allah (proofs, evidence, verses, lessons, signs, revelations, etc.) while Allah is Witness to what you do?"

(14) And hold fast, all of you together, to the Rope of Allah (i.e. this Qur'an), and be not divided among yourselves , and remember Allah's Favour on you, for you were enemies one to another but He joined your hearts together, so that, by His Grace, you became brethren (in Islamic Faith), and you were on the brink of a pit of Fire, and He saved you from it. Thus Allah makes His Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.,) clear to you, that you may be guided.

(15) Indignity is put over them wherever they may be, except when under a covenant (of protection) from Allah, and from men; they have drawn on themselves the Wrath of Allah, and destruction is put over them. This is because they disbelieved in the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of Allah and killed the Prophets without right. This is because they disobeyed (Allah) and used to transgress beyond bounds (in Allah's disobedience, crimes and sins).

(16) Surely! Those who disbelieved in Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), We shall burn them in Fire. As often as their skins are roasted through, We shall change them for other skins that they may taste the punishment. Truly, Allah is Ever Most Powerful, All-Wise.

(17) Because of their breaking the covenant, and of their rejecting the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of Allah, and of their killing the Prophets unjustly, and of their saying: "Our hearts are wrapped (with coverings, i.e. we do not understand what the Messengers say)" - nay, Allah has set a seal upon their hearts because of their disbelief, so they believe not but a little.

(18) And those who disbelieve and deny our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) are those who will be the dwellers of the Hell-fire.

(19) The Messiah ['Îsa (Jesus)], son of Maryam (Mary), was no more than a Messenger; many were the Messengers that passed away before him. His mother [Maryam (Mary)] was a Siddiqah [i.e. she believed in the Words of Allah and His Books (see Verse 66:12)]. They both used to eat food (as any other human being, while Allah does not eat). Look how We make the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) clear to them; yet look how they are deluded away (from the truth).

(20) But those who disbelieved and belied Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), they shall be the dwellers of the (Hell) Fire.