It has been related that the Messenger of Allah (may Allah bless him and grant him peace) said:
Allah created the intellect from a stored-up light which was hidden within His fore-knowledge, and neither emissary, prophet nor high-ranking angel has seen it. Then He made knowledge its 'self', understanding its spirit, abstension (zuhd) its head, modesty (haya') its eyes, wisdom its tongue, compassion (ra`fah) its purpose, and mercy its heart.
In al-Tahdhib: From what has been confirmed to be from the sunnah; The Holy Prophet (may Allah bless him and grant him peace) would look for the crescent of the new moon and undertake the responsibility for trying to spot the new moon himself.
Khalif ibn Ayyub al-`amiri narrated about the Holy Prophet (may Allah bless him and grant him peace):
When the month of Ramadhan would enter, he would grow pale and his prayers would increase and he would supplicate and beseech Allah entreatingly."
`Anbasah al-`Abidi said, "The Noble Prophet passed away while (continuing the practice of) fasting in the month of Sha`ban and Ramadhan, and three days in every (other) month."
From al-Imam as-Sadiq (peace be upon him) from his fathers (peace be upon them): "One day the Holy Prophet asked his companions: "Who from among you fasts the (whole) lifetime?" Salman said, "I do, O Prophet of Allah." A man said to Salman: "I have seen you eating on most days!" He said: "It is not as you think. I fast on three days every month (and) Allah has said, 'Whoever performs a good deed he shall have ten like it...' and I join Sha`ban with Ramadhan, so this is fasting of the lifetime.
And he also narrated: "The first thing the Noble Prophet broke his fast with in the season of fresh dates were fresh dates and in the season of dry dates were dry dates."
And also: "It is recommended to have the suhur (morning meal before the fast) even if it is only a glass of water. It is narrated that it is better to have dry dates and `al-Sawiq1 because this is what the Holy Prophet used to have in his suhur."
In al-Faqih: When the month of Ramadhan entered, the Noble Prophet freed all the prisoners and gave (something) to all of the beggars.
Abi Basir said, "When the last ten nights (of the month of Ramadhan) would enter, he (may Allah bless him and grant him peace) would prepare himself, leave his wives, keep awake at night and occupy himself with worship."
1. A dish made from wheat or barley mixed with sugar and dates.
The Messenger of Allah (peace and blessings be upon him) quizzed his companions one day, asking:
"Which is the most fundamental and basic tenet of faith?"
One student answered, "Salat (prayer)"
"No," the Prophet replied.
Another answered, "Zakat (almsgiving)"
"No"
Another answered, "Fasting."
"No"
Yet another, "Hajj and Umrah (pilgrimage)"
The Prophet said, "No"
And the last student answered, "Jihad (struggle)."
The Prophet remarked, "Not even that."
Finally, the Messenger of Allah explained, "All of those tenets mentioned by you are beautiful acts of worship and obedience. But they do not measure up with what I have in mind. Remember, the basic and fundamental tenet is to love for the sake of Allah and to hate for the sake of Allah. All your likes and dislikes must conform with His pleasure."