question #1 Sahih al-Bukhari 174, Book 4, Hadith 40 : What was the practice regarding the presence of dogs in mosques during the time of the Prophet Muhammad (ﷺ)?

My father said. “During the lifetime of Allah’s
Apostle, the dogs used to urinate, and pass through the mosques (come
and go), nevertheless they never used to sprinkle water on it (urine
of the dog.)”