Verse 2:197 of Holy Quran
Hajj is [during] well-known months, so whoever has made Hajj obligatory upon himself therein [by entering the state of ihram], there is [to be for him] no sexual relations and no disobedience and no disputing during Hajj. And whatever good you do - ALLAH knows it. And take provisions, but indeed, the best provision is fear of ALLAH. And fear Me, O you of understanding.
In the above ayat (verse) related to pilgrimage Hajj, the need to perform circumambulation or tawaaf (ritual walk around the Holy Kaaba), saaee (ritual of running between the hills of Safa and Marwa), stoning of the shetan that is Rami-al-jamaraat are some rituals of Hajj, ALLAH Almighty mentions the need to refrain from 3 acts:
lewd means any talk which is rude, offensive vulgar or abuse. To speak in such a manner violates the holiness of Hajj. It does not suit a Muslim to speak in a lewd manner; it only suggests a filthy mind and heart. This prohibition during Hajj also includes speaking badly about any one or fighting with others
this includes any act or action of disobedience to ALLAH Almighty particularly not lowering one's gaze. During Hajj, being such a large gathering of women and men, the need to lower one's gaze becomes all the more vital. Not lowering the one's gaze not only destroys the holiness of Hajj, but one's attention is also diverted from ALLAH Almighty towards the creation. Nothing is attained by the stray gaze; it is an arrow which returns only to pierce one's own heart.
the sacred Hajj journey makes the most forbearing and patient of people irritable because one's eating and sleeping patterns are disrupted. In such a situation and in such a huge gathering of people one can be easily provoked and get or involve into an argument. At such times a person should exercise self-discipline and patience and remind him by saying 'I am in Hajj' i.e. I am in a sacred state.
These above mentioned 3 sins reflect the 3 main categories of sins that a Muslim should avoid throughout his life i.e.
During pilgrimage Hajj and umrah these 3 sins are especially very dangerous yet so easy to commit. If any person engages in any of these above mentioned sins then there is a great danger that all of the reward and blessings for Hajj and Umrah will be destroyed or vanished. As well as fulfilling all the rituals and rites of umrah and Hajj, it is essential to refrain from the above sins for an accepted pilgrimage Hajj and umrah.