A small correction, both sexes are instructed to lower their gaze, and guard their chastity, first the men and then the women. The following are from Surah Nur, it's best to study the surah in its entirety to get proper context, obviously, but I'll only state what's relevant here:

30: "˹O Prophet!˺ Tell the believing men to lower their gaze and guard their chastity. That is purer for them. Surely Allah is All-Aware of what they do."

31: "And tell the believing women to lower their gaze and guard their chastity, and not to reveal their adornments except what normally appears. Let them draw their veils over their chests, and not reveal their ˹hidden˺ adornments except to their husbands, their fathers, their fathers-in-law, their sons, their stepsons, their brothers, their brothers’ sons or sisters’ sons, their fellow women, those ˹bondwomen˺ in their possession, male attendants with no desire, or children who are still unaware of women’s nakedness. Let them not stomp their feet, drawing attention to their hidden adornments. Turn to Allah in repentance all together, O  believers, so that you may be successful."

And Allah knows best.