The Messenger of Allah (sal Allahu alaihi wa sallam) said:
“On no other days are good deeds more beloved to Allah than on these ten days (the first ten days of Zil Hijjah).” The Sahabah (radi Allahu anhum) asked, “O Messenger of Allah! Not even Jihad for the sake of Allah?” The Messenger of Allah (sal Allahu alaihi wa sallam) replied: “Not even Jihad in the way of Allah, except in the case of a man who went out to fight giving himself and his wealth up for the cause, and came back with nothing (i.e. was martyred).” [Bukhari]
“Praise be to Allah Who has created Time and has made some times better than others, some months and days and nights better than others, when rewards are multiplied many times, as a mercy towards His slaves. This encourages them to do more righteous deeds and makes them more eager to worship Him, so that the Muslim renews his efforts to gain a greater share of reward, prepare himself for death and supply himself in readiness for the Day of Judgement.
“This season of worship brings many benefits, such as the opportunity to correct one’s faults and make up for any shortcomings or anything that one might have missed. Every one of these special occasions involves some kind of worship through which the slaves may draw closer to Allah, and some kind of blessing though which Allah (subhana wa ta’ala) bestows His favour and mercy upon whomsoever He wills. The happy person is the one who makes the most of these special months, days and hours and draws nearer to his Lord during these times through acts of worship; he will most likely be touched by the blessing of Allah and will feel the joy of knowing that he is safe from the flames of Hell.” [Ibn Rajab, Al-Lataa’if].