Abu Dawud Bk.2, Number 0450:


Narrated Uthman ibn Abul'As:

The Prophet (nay peace be upon him) commanded him to build a mosque at Ta'if where the idols were placed.

Abu Dawud Bk. 2, Number 0461:


Narrated Anas ibn Malik:

The Prophet (peace_be_upon_him) said: The rewards of my people were presented before me, so much so that even the reward for removing a mote by a person from the mosque was presented to me. The sins of my people were also presented before me. I did not find a sin greater than that of a person forgetting the Qur'anic chapter or verse memorised by him.

Abu Dawud Bk.2, Number 0481:


Narrated Ubadah ibn as-Samit:

We came to Jabir ibn Abdullah who was sitting in his mosque. He said: The Apostle of Allah (peace_be_upon_him) came to us in this mosque and he had a twig of date-palm of the kind of Ibn Tab. He looked and saw phlegm on the wall towards qiblah. He turned to it and scraped it with the twig.

He then said: Who of you likes that Allah turns His face from him? He further said: When any of you stands for praying, Allah faces him. So he should not spit before him, nor on his right side. He should spit on his left side under his left foot. If he is in a hurry (i.e. forced to spit immediately), he should do with his cloth in this manner. He then placed the cloth on his mouth and rubbed it off.

He then said: Bring perfume. A young man of the tribe stood and hurried to his house and returned with perfume in his palm. The Apostle of Allah (peace_be_upon_him) took it and put it at the end of the twig. He then stained the mark of phlegm with it.

Jabir said: This is the reason you use perfume in your mosques.

Muslim uto- uto 

Abu Dawud 02, Number 0485:


Narrated Wathilah ibn al-Asqa':

AbuSa'id said: I saw Wathilah ibn al-Asqa' in the mosque of Damascus. He spat at the mat and then rubbed it with his foot. He was asked: Why did you do so? He said: Because I saw the Apostle of Allah (peace_be_upon_him) doing so.