Is what a friend does—accompanying girls and going out with them, without physical transgression, and with his claim of no romantic feelings—forbidden by Islamic law, and what are the proofs for this from the Qur’an and Sunnah?

The religious evidence on the prohibition of relationships between non-mahram men and women is interwoven, and such relationships are considered void in Islamic law, for several reasons, including:

1. Allah Almighty's saying: "And when you ask [his wives] for something, ask them from behind a partition. That is purer for your hearts and their hearts." The wisdom behind the hijab is the purity of hearts from suspicion. 2. Allah Almighty's command to lower the gaze, as He says: "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." Friendship between the sexes may lead to unrestrained gazing and what follows. 3. The prohibition of approaching unlawful sexual intercourse, as Allah Almighty says: "And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way." The prohibition includes everything that leads to unlawful sexual intercourse, and friendship between the sexes is a strong means of falling into indecencies. 4. Blocking the means (sadd al-dhara'i'): Islamic law blocks the causes that lead to temptation unless a greater benefit overrides them. Looking at the face of a non-mahram woman and being in seclusion with her are prohibited out of fear of temptation. 5. The prohibition of entering upon women, as the Messenger of Allah, peace and blessings be upon him, said: "Beware of entering upon women." If merely entering is prohibited, then what about companionship and prolonged sitting? 6. Islamic law encourages separation between the sexes even in the most honorable places and acts of worship, such as prayer, as the Messenger of Allah, peace and blessings be upon him, said: "The best rows for men are the first ones, and the worst are the last ones. The best rows for women are the last ones, and the worst are the first ones."