بسم الله الرحمن الرحيم

In explanation of the supplication for entering toilet, Shaykh Uthaymeen (rahimahullah) brought the following benefit.

It is said that the place for relieving oneself is dirty, and every place which is similar is the abode of the shayateen, due to His statement The Most High, 

الْخَبِيثَاتُ لِلْخَبِيثِينَ وَالْخَبِيثُونَ لِلْخَبِيثَاتِ 

Bad statements are for bad people (or bad women for bad men) and bad people for bad statements (or bad men for bad women). (1)

In explanation of this ayah, Imam as-Sadi (rahimahullah) said, “Every evil man and woman, statement and action is fitting, in agreement and similar to each other.” (2)

And this is from the wisdom of Allah, that he has made the evil souls incline to each other. And the righteous souls incline to each other, due to this the place of the angels is the masaajid, the masaajid are righteous places and their purpose is for the worship of Allah. 

Ad-Duroos al-Fiqhiyya min al-Muhaadaraat al-Jaami’eeyah Slightly Paraphrased 

(1) An-Noor:26 Translation by Muhsin Khan

(2) Tayseer al Kareem ar Rahman pg.658