As a matter of fact, all divine religions prohibit lustful leer at the members of the opposite gender outside marriage, especially when marriage with the intended member is unlikely like the case of married persons.
We observe that the prohibition of lustful leer is one of the Ten Commandments in the Torah. Such prohibition is repeated more than once in the Old Testament. We read: “Thou shalt not covet thy neighbor’s house, thou shalt not covet thy neighbor’s wife, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor any thing that is thy neighbor’s.” (Exodus 20:17, Deuteronomy 5:21)
In the New Testament, we notice that lustful looking at a woman is deemed to be tantamount to adultery. No wonder, lustful looking is more likely to lead to adultery. Adultery is more likely to be preceded by lustful looking.
We read: “You have heard that it was said to the people long ago, ‘Do not murder,’ and ‘anyone who murders will be subject to judgment.’ But I tell you that anyone who is angry with his brother will be subject to judgment…You have heard that it was said, ‘Do not commit adultery.’ But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.” (Matthew 5:21-22, 27-28 (NIV))
The Qur’an orders Prophet Muhammad to tell Muslims, men and women, to abstain from looking at each other lustfully and maintain their purity. In the Qur’an, we read the following verses:
Tell the believing men to reduce [some] of their vision and guard their private parts. That is purer for them. Indeed, Allah is Acquainted with what they do. And tell the believing women to reduce [some] of their vision and guard their private parts… (An-Nur 24:30-31)
Prophet Muhammad indicated that the unintentional look is forgiven but a Muslim should not follow up such an unintentional look with an intentional one for the latter is not forgiven like the former.
It is reported that Prophet Muhammad said: “Do not follow a look at a woman with another. Verily, only the first one is for you but not the second.” (Ahmad)
Since sitting down at the sides of the streets is more likely to involve looking at the passersby, including women and girls, Prophet Muhammad warned against it. However, when the Companions argued that this is unavoidable, he instructed them to avoid gazing at the passersby as a part of the street etiquette.
Abu Sa`id Al-Khudri narrated that the Prophet said, “Beware! Avoid sitting on roads.” They (the people) said, “O Messenger of Allah! We can’t help sitting (on roads) as these are (our places) where we have talks.” The Prophet said, “lf you refuse but to sit, then pay the road its right.” They said, “What is the right of the road, O Messenger of Allah?” He said, “Lowering your gaze, refraining from harming others, returning greeting, and enjoining what is good, and forbidding what is evil.” (Al-Bukhari)
Prophet Muhammad admired the following verse composed by Antarah, the pre-Islamic poet:
“I lower my gaze wherever my female neighbor appears to me until my female neighbor gets into her home.”
Prophet Muhammad admired this verse for it calls for good manners, especially decency.
1- The Glorious Qur’an (Sahih International Translation)
2- Sahih Al-Bukhari
3- Munad Al-Imam Ahmad
4- The Holy Bible (Visit biblegateway.com)