What is legislated for a Muslim to do during the first ten days of Dhul-Hijjah?

The first ten days of Dhu al-Hijjah are blessed days, by which Allah swore in His Book. Righteous deeds performed during them are more beloved to Allah than those performed at other times, including jihad in the way of Allah, except for one who goes out with his life and wealth and returns with neither. Therefore, a Muslim should strive in worship during these days, such as prayer, reciting the Quran, remembrance of Allah (dhikr), seeking forgiveness (istighfar), and maintaining kinship ties. The most emphasized of these acts is fasting, especially fasting on the Day of Arafat, which expiates sins for two years. It is disliked for anyone intending to offer a sacrifice (udhiyah) to cut any of their hair or clip their nails upon sighting the crescent moon of Dhu al-Hijjah.