Casting Evil Glances is cursed by Nabi

The one who casts evil glances is cursed by Nabi ﷺ. Nabi ﷺ says in a Hadith mentioned in Mishkaat Shareef:
لعن اللہ الناظر والمنظور الیھ
“May the curse of Allah be upon the one who casts evil glances and upon the one who presents him/herself to be looked at.” (Mishkaat; Pg. 270)
If casting evil glances was a minor sin, then Nabi ﷺ, being a mercy to mankind would not have cursed its perpetrator. The curse of Nabi ﷺ is clear proof that this is a very despicable crime. The meaning of curse is to become distant from the mercy of Allah. Imam Raghib Isfahani mentions in Mufradaatul Qur’aan that the definition of لعنة (curse) is:
البعد عن الرحمة
“To become distant from mercy.”
Thus, he who has become distant from the mercy of Allah Ta’ala, cannot gain salvation from the evils of his Nafs. Only he who is under the shade of Allah’s mercy can attain salvation from the evils of the Nafs. Allah Ta’ala says:
ان النفس لامارة بالسوء
The Nafs abundantly commands evil.”
(Sura Yousuf; Ayat 53, Juz 13)
So how is it possible to be saved from the evils of Nafs? Allah Ta’ala further says:
الا مار حم ربی
“Expect by the mercy of my Lord”.

From this, we understand that the only way to be saved from the evils of the Nafs is to come under the shade of Allah’s mercy. Allah Ta’ala who is the Creator of this Nafs Himself has proclaimed that those who are in His mercy will be saved. Therefore, the one who has come under the shade of الا مارحم ربی his Nafs did not remain امارة بالسوء (excessively commanding evil) rather it became امارة بالخیر (abundantly commanding good). This is why after the command of guarding the eyes, یغضوا من ابصارھم , Allah Ta’ala mentions, ویحفظوا فروجھم “Guard the private parts.” Because through the blessings of fulfilling the divine command of Allah Ta’ala and saving oneself from the curse of Nabi ﷺ one comes under the shade of Allah’s mercy. Now his private parts will also be safeguarded. Form this we conclude that the reward of guarding the eyes is that the private parts become safeguarded. On the contrary, if a person does not guard his eyes then he cannot guard his private parts either and curses which descends upon him is a separate punishment on its own.

From Blog - Khanqah Imdadia Ashrafia

Harms Of Casting Evil Glances

The question arises as to what is the root of all these problems. May Allah Ta'ala reward our Masha'ikh and pious predecessors, who look at the world with the eye of the heart, enlightened by the light of the Qur’aan, Hadith and the burning love of Allah Ta’ala. They have diagnosed all these sickness to be brought about by one deadly disease. The root of all these problems is the SIN OF THE EYES, casting evil glances, looking at the opposite or same sex with lustful gazes.

Unfortunately today, people do not even consider casting evil glances to be a sin, when in actuality it is the root of innumerable vices and sins. Another reality which people are totally unaware of is that by protecting one's eyes from lustful glances, one is promised the taste of the sweetness of Imaan. Once the sweetness of Imaan enters the heart, it will never be taken back. Thus by protecting the eyes, one is given grad tidings of a good death. Rasulullah said:

"Verily the evil glance is a poisonous arrow from the arrows of Iblees. He who abstains from casting evil glances, I will grant him such Imaan, that he will feel the sweetness of it in his heart". (Narrated by Ibn Mas’ud in Tabarani and Kanzul-Ummaal; Vol. 5, pg. 228), (Ibn Katheer; Surra Nur, Ayat 30)

Harm No. 1: Disobedience of Allah

Casting evil glances is clearly forbidden by the  clear and explicit text of the Qur'aan. Allah Ta'ala says:

O Nabi (
  SAW  ) Tell the believing men to lower their gazes." (Sura Nur ; Ayat 30, Juz 18)

Therefore he who casts evil glances, is opposing the clear and explicit command of Qur'aan, and one who opposes the clear and explicit command of Qur'aan is guilty of committing a HARAAM act. Thus, to save oneself from this sin, it is sufficient to meditate upon the fact that the one who casts evil glances is opposing a commandment of the Qur’aan. In other words, he is disobeying Allah Ta'ala.

Source: Khanqah Ashrafiya