The Meaning of Vengeance
Intiqam linguistically: is enacting penalty and punishment. It is said, ‘Allah have vengeance upon him’ to mean, ‘May He punish him.’ Naqamtu al-amra wa naqimatuh is said if one finds something defective and severely dislikes it due to some evil it has. Its noun is niqmah, the plural of which is naqimat and niqam.  al-Sihah, al-Jawhari (5/2045); Lisan al-`Arab, Ibn Manzur (12/590); al-Misbah al-Munir, al-Fayyumi (2/623).
Intiqam technically: is exacting retribution with hatefulness to the level of wrath, and removing blessings through punishment.  al-Furuq al-Lughawiyyah, al-`Askari (p. 77); Nadrat al-Na`im, a number of authors (9/4007). The Difference between Vengeance and Penalty (`Iqab)  al-Furuq al-Lughawiyyah, al-`Askari (p. 34, 77).
Vengeance is taking away another's blessing through punishment. Penalty is recompense for criminality through punishment. Penalty is the opposite of reward (thawab). Revenge is the opposite of bestowal (In`am).Dispraise of Vengeance and Warning towards it in the Qur’an and Sunnah
❖ Allah, exalted, says: “Whoever has assaulted you, then assault him in the same way that he has assaulted you.” al-Baqarah: 194.
❖ al-Sa`di said: “Since the self - generally - does not stop at its limit if it is allowed to seek its own punishment due to its desire for retribution - meaning: vengeance -, Allah, exalted, commanded that souls must be mindful of Him, which effectively is to halt at His limits and not overstep them. He has said, exalted, that He is “with the pious” al-Baqarah: 194, meaning, He is in their aid, support, help, and causing their success.”  Tafsir al-Sa`di (p. 89).
❖ Allah, exalted, also says: “When they are angry, they forgive.” al-Shura: 37.
❖ `A’ishah, Allah be pleased with her, said: “Allah’s Messenger ﷺ was never given a choice between two matters but that he chose the easier of the two so long as it was not useful. If it was, he was the furthest of people from it. Likewise, the Messenger of Allah ﷺ never sought vengeance for himself. Only if Allah’s sanctity was desecrated, then he would seek revenge for that for the sake of Allah.”  Reported by al-Bukhari (3560) and the wording is his, as well as Muslim (2327). Meaning, he ﷺ never sought retribution for his own ego, rather exacted it when what is sacrosanct to Allah was violated, in which case he would seek the punishment of the transgressor due to that.  Mirqat al-Mafatih, `Ali al-Qari (9/3716).
❖ `Iyad ibn Himar, Allah be pleased with him, said: “I said: ‘Prophet of Allah, a person from my own people insults me despite him being lesser than I am, should I avenge myself against him?’ The Prophet ﷺ said: “Those who insult each other are two devils, cursing and lying against each other.”  Reported by Ahmad (17524), Ibn Hibban (5726) and the wording is his, and al-Tabarani (17/365) (1001). al-Albani authenticated it in Sahih al-Jami` (9179). Quotes of the Predecessors and Scholars on Vengeance
❖ Mu`awiyah said to his son upon seeing him strike some servant of his: “Beware, my son, of seeking retribution from the one who has no means against you. By Allah, power has acted as a barrier between your father and those of his rank. It is for this that it was said: ‘Power does away with one’s reservation.’”  al-Tadhkirah al-Hamduniyyah (2/138).
❖ Ibn al-Qayyim said: “No one has ever sought revenge for his ego except that his vengeance was followed by regret.”  Madarij al-Salikin, Ibn al-Qayyim (2/303).
❖ Some of those of eloquence said: “It is not the habit of the magnanimous to hastily exact retribution, nor is it a condition of magnanimity the removal of blessings.”  Adab al-Dunya wa al-Din, al-Mawardi (1/320). Categories of Vengeance
Vengeance is two categories:
The first: is praiseworthy vengeance, and this is when Allah’s sanctity is desecrated.
The second: is blameworthy vengeance, which is acting for the self’s desires and its ego.Impacts of Vengeance
There are negative effects and harms of revenge which come back to the one exacting it. Among those are: The possessor of this quality does not attain ascendancy nor prestige. It is not suitable to show gratitude to the avenger nor mention him in praise. Revenge is followed by regret. It begets malice and spite between people. Reasons for Falling into Vengeance
Not adorning oneself with forbearance or patience. Not adorning oneself with pardon and absolution. Not being able to restrain one’s anger. Some of the ignorant referring to revenge as courage, manliness, honour, and aspiration; continually naming it with these names stupidly and ignorantly until it seems beautiful to the self and it leans towards it. The vengeful being truly subjected to harm by the one against whom he seeks vengeance. The absence of justice, and there being no means to take the right of the oppressed, forcing him to seek his own retribution which may lead him to take back more than his right. Means to Desisting from Vengeance  Jami` al-Masa’il, Ibn Taymiyyah (1/170).
Remembering Allah’s vengeance from those who disobey Him. Pardoning and absolving others. Restraining anger. Avoiding mockery and ridicule. Fear of wasting one’s life, having one’s heart disperse upon one missing true benefit. Realising that vengeance increases the enemy’s evil. Not allowing the heart to become busy with it or contemplate it. Returning to Allah and sincerity to Him at all times. Anger, for revenge is often at the former’s height. Adages, Proverbs, and Poetry about Vengeance  Jamharat al-Amthal, al-`Askari (p. 494); Majma` al-Amthal, al-Maydani (1/421); Mu`jam al-Lughat al-`Arabiyyat al-Mu`asirah, Ahmad Mukhtar (1/309).
❖ “The most lowly deed of the powerful is vengeance.”
❖ “He whimpered to me, he’s a whimperer.” It is a parable struck to the one who cannot avenge himself except by screaming at others.
❖ “Pardoning is the most powerful form of revenge.”
❖ The poet said:
“When they avenge, they announce it,
But if they bestow, they bestow quietly.
The sitting stand to them upon their arrival;
Yet, their gravitas sits when they stand.”  Adab al-Dunya wa al-Din, al-Mawardi (p. 203).