The Prophet Muhammad صلى الله عليه وآله وسلم said:
عَامَّةُ عَذَابِ الْقَبْرِ مِنَ الْبَوْلِ ، فَاسْتَنْزِهُوا مِنَ الْبَوْلِ
"Most of the punishment of the grave is due to urine, therefore beware of urine" (Musnad al Bazaar)
According to the teachings of Islam from the Quran and Sunnah, urine is impure and must be strictly avoided. A person who did not take care to keep his garments soiled from his urine was being punished in the grave. However, according to the Hanafi jurisprudence, a small amount of urine and stool from a rat is exempted from being removed if it is mixed with food or stains someone's clothing. From this we can see how the Hanafi jurisprudence contravenes the clear guidance of Quran and Sunnah.
ولو رضيعا والذئب وبول الفأرة ينجس الماء لإمكان الاحتراز عنه لأنه يخمر ويعفى عن القليل منه ومن خرئها في الطعام والثياب للضرورة
Reference: Maraqi al-Falah Page #62