Among the points that are often needed is his statement under number 5: “If, after a man finishes his prayer, he notices some impurity on his clothing or body of which he had been unaware, his prayer remains valid and he does not have to repeat it.”

I say: The evidence for this part of his words is the hadith of Abu Saʿīd al-Khudrī who said:

While the Messenger of Allah (peace and blessings be upon him) was praying with his Companions, he suddenly removed his sandals and placed them to his left. When the people saw this, they too took off their sandals. When the Messenger of Allah (peace and blessings be upon him) had finished the prayer he asked, “What made you throw down your sandals?” They replied, “We saw you take off your sandals, so we took off ours.” He said, “Gabriel (peace be upon him) came to me and informed me that there was filth on them.” He then added, “When one of you comes to the mosque, let him look; if he sees filth or dirt on his sandals, let him wipe it off and pray in them.”

Narrated by Abū Dāwūd, Aḥmad, and others with a sound chain; it is recorded in Irwāʾ al-Ghalīl, no. 284. The author cited it just before this section without commenting on it!