Sa'id ibn al-Musayyib سعيد بن المسيب بن حزن أبو محمد القرشي · The Book on Fasting

he asked Ibn Al-Musaiyab about fasting on a journey, so he narrated to him that Umar bin Al-Khattab said: "We fought in two battles along with the Messenger of Allah during Ramadan; the Day of Badr, and the Conquest (of Makkah), so we broke our fast during them."

the Prophet said: "There are no days more beloved to Allah that He be worshipped in them than the ten days of Dhul-Hijjah, fasting every day of them is the equivalent of fasting a year, and standing every night of them (in prayer) is the equivalent of standing on the Night of Qadr."

The Messenger of Allah said: "Indeed your Lord said: 'Every good deed is rewarded with ten of the same up to seven hundred times over. Fasting is for Me, and I shall reward for it.' Fasting is a shield from the Fire. The smell coming from the mouth of the one fasting is more pleasant to Allah than the scent of musk. If one of you is abused by an ignorant person while fasting, then let him say: 'Indeed I…

"The Prophet would perform I'tikaf during the last ten (days) of Ramadan until Allah took him."