The Verbal Sunna. This category consists of the Messenger's words, which provide a basis for many religious commandments. To cite a few examples:
• "No bequest to the heir."  In other words, people cannot bequeath any of their wealth to their heirs, since they will naturally inherit the bulk of the estate. A bequest can be made to the poor or some social service institutions.
• "Don't harm (others), and don't return harm for harm."  That is, do not engage in any negative and damaging behavior toward others, and do not retaliate against them by returning bad for bad.
• "A tenth will be given (out of crops grown in fields) watered by rain or rivers; but a twentieth (out of those grown in fields) watered by people (irrigation or watering)."  The Qur'an enjoins charity, but goes into no detail about how to do so correctly. All such regulations were established by the Sunna.
• "A sea is that of which the water is clean and the dead animals are lawful to eat." He gave this response when someone asked him if wudu' could be done with sea-water. This has provided a basis for many other rulings.
The Practical Sunna. The Qur'an usually lays down only general rules and principles. For example, it enjoins prayer and pilgrimage but does not describe in detail how to perform them. The Messenger, taught by God through inspiration or through Gabriel, provided this information through his actions. His life was one long, unique example to be followed by all Muslims. For example, he led the daily prayers before his Companions five times a day and ordered them to pray as he prayed. 
The Sunna based on approval. The Messenger corrected his Companions' mistakes usually by ascending the pulpit and asking: "Why has somebody done this?"  When he saw something agreeable in them, he gave his approval either explicitly or by keeping silent. For example:
• Two Companions traveling in the desert could not find enough water for wudu' before praying, and so used sand (tayammum). When they found water later on before the prayer's time had passed, one of them performed wudu' and repeated the prayer, and the other did not. When they asked The Messenger about it later, he told the one who had not repeated the prayer: "You acted in accordance with the Sunna." Then, he turned to the other one and said: "For you, there is double reward." 
• The Messenger ordered a march upon the Banu Qurayza immediately after the Battle of the Trench. He said: "Hurry up! We'll perform the afternoon prayer there." Some Companions, concluding that they should hasten and pray over there started out without delay. Others understood that they were to hasten to the Banu Qurayza's territory only, and that they could pray before departing. The Messenger approved of both interpretations. 
 Ibn Hanbal, Musnad, 1:313.
 Tirmidhi, "Zakat," 14; Bukhari, "Zakat," 55.
 Bukhari, "Adhan," 18; Ibn Hanbal, 5:53.
 Bukhari, "Salat," 70; Muslim, "Nikah," 5.
 Darimi, "Tahara," 65; Abu Dawud, "Tahara," 126.
 Darimi, "Maghazi," 30, "Khawf," 5.