If anyone forgets a prayer he should pray that prayer when he remembers it. There is no expiation except to pray the same." Then the prophet (peace be upon him) recited: "Establish prayer for My (i.e. Allah's) remembrance.[(20.14).]"

Sahih Al-Bukhari Vol. 1 : No. 571

Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: The rider should first greet the pedestrian, and the pedestrian the one who is seated and a small group should greet a larger group (with as-Salam-u-'Alaikum).

Muslim :: Book 26 : Hadith 5374

Abu Sa'id Khudri reported Allah's Apostle (may peace be upon him) as saying: Avoid sitting on the paths. They (the Companions) said: Allah's Messenger, we cannot help but holding our meetings (in these paths) and discuss matters (there). Thereupon Allah's Messenger (may peace be upon him) said: If you insist on holding meetings, then give the path its due right. They said: What are its due rights? Upon this he said: Lowering the gaze, refraining from doing harm, exchanging of greetings, commanding of good and forbidding from evil.

Muslim :: Book 26 : Hadith 5376

A'isha, umm al-muminin (may Allah swt please with her) said, "The Messenger of Allah, may Allah bless him and grant him peace, used to pray thirteen rakas in the night and then would pray two rakas when he heard the adhan for the morning prayer."

Malik :: Book 7 : Hadith 7.2.10

Muadh ibn Jabal (may Allah swt please with him) said, "The last advice the Messenger of Allah, may Allah bless him and grant him peace, gave me when I put my foot in the stirrup was that he said, 'Make your character good for the people, Muadh ibn Jabal!' "

Malik :: Book 47 : Hadith 47.1.1

The Jews were split up into seventy-one or seventy-two sects; and the Christians were split up into seventy one or seventy-two sects; and my community will be split up into seventy-three sects.

Dawud :: Book 40 : Hadith 4579

I came to the Prophet (peace be upon him) and his companions were sitting as if they had birds on their heads [means the were sitting in attentive posture out of respect to the Prophet (peace be upon him)]. I saluted and sat down. The desert Arabs then came from here and there. They asked: Apostle of Allah, should we make use of medical treatment? He replied: "Make use of medical treatment, for Allah has not made a disease without appointing a remedy for it, with the exception of one disease, namely old age".

Dawud :: Book 28 : Hadith 3846

 "Angels come to you in succession by night and day and all of them get together at the time of the Fajr and 'Asr prayers. Those who have passed the night with you (or stayed with you) ascend (to the Heaven) and Allah 

asks them, though He knows everything about you, well, "In what state did you leave my slaves?" The angels reply: "When we left them they were praying and when we reached them, they were praying."

-- Sahih Al-Bukhari Vol. 1 : No. 530

 "Whoever misses the 'Asr prayer (intentionally) then it is as if he lost his family and property."

Sahih Al-Bukhari Vol. 1 : No. 527