Knowledge Every Muslim Should Know (Book One)

The Virtues of the First Ten Days of Dhu-AlHijjah

 THE VIRTUES OF THE FIRST TEN DAYS OF DHU-ALHIJJAH

        Among the great seasons of worship are the first ten days of Dhu-AlHijjah, which Allah (Glorified and Praised is He) has favored over other days. It was narrated from Ibn Abbas (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said, “There are no days on which righteous deeds are more beloved to Allah than these ten days.” They asked, “Not even jihad for the sake of Allah?” He replied, “Not even jihad for the sake of Allah, unless a man goes out himself for jihad taking his wealth with him and does not come back with anything(1).”
        It was also narrated from Anas (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said, “There is no deed that is better before Allah or more greatly rewarded than a good deed done in the (first) ten days of AlAdha.” It was asked, “Not even jihad for the sake of Allah?” He replied, “Not even jihad for the sake of Allah, unless a man goes out himself for jihad taking his wealth with him and does not come back with anything(2).”
        These texts and others indicate that these ten days are better than all other days of the year, with no exception, even the last ten days of Ramadhaan. But the last ten nights of Ramadhaan are better than the first ten nights of Dhu-AlHijjah, because they include Laylat AlQadr, which is better than a thousand months.
        So the Muslim should start these days with sincere repentance to Allah (Glorified and Praised is He), then he should do a lot of righteous deeds in general, then he should pay attention to doing the following deeds:

Fasting
        It is sunnah for a Muslim to fast on the first nine days of Dhu-AlHijjah, because the Prophet (peace and blessings of Allah be upon him) encouraged us to do righteous deeds in the first ten days of Dhu-AlHijjah, and fasting is one of the best of deeds, which Allah has chosen for Himself(3).
        It was narrated from Hunaydah ibn Khalid from his wife, that one of the wives of the Prophet (peace and blessings of Allah be upon him) said, “The Prophet (peace and blessings of Allah be upon him) used to fast on the first nine days of Dhu-AlHijjah and the day of Ashoora, and three days each month, the first Monday of the month and two Thursdays(4).

Reciting tahmeed, tahleel and takbeer abundantly
        It is sunnah to recite takbeer (saying Allahu akbar [Allah is most great]), tahmeed (saying alhamdu lillah [praise be to Allah]), tahleel (saying Laa ilaaha illa Allah [There is no god but Allah]) and tasbeeh (saying Subhaan Allah [Glory be to Allah]), during the first ten days of Dhu-AlHijjah, saying these words out loud in the mosques, homes, streets and every place in which it is permissible to remember Allah (Glorified and Praised is He), to perform this act of worship openly and proclaim the greatness of Allah (Glorified and Praised is He).
        Men should recite out loud and women should recite quietly.
        Allah says: “That they may witness benefits for themselves and mention the name of Allah on known days over what He has provided for them of [sacrificial] animals. So eat of them and feed the miserable and poor[al-Hajj 22:28]”
        The majority are of the view that the “appointed days” are the first ten days of Dhu-AlHijjah, because it was narrated from Ibn Abbas (may Allah be pleased with him) that the appointed days are the first ten days of Dhu-AlHijjah.
        It was narrated from Abdu-Allah ibn Umar (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said, “There are no days that are greater before Allah or in which good deeds are more beloved to Him, than these ten days, so recite a great deal of tahleel, takbeer and tahmeed during them(5).”
        The takbeer is as follows:
        Allahu akbar, Allahu akbar, laa illaha illa Allah, Allahu akbar, wa lillaah alhamd (Allah is the Greatest, Allah is the Greatest; there is no god but Allah; Allah is the Greatest and to Allah be praise).

Doing Hajj and Umrah
        One of the greatest deeds that can be done during these ten days is Hajj to the sacred House of Allah (Glorified and Praised is He). Whoever Allah (Glorified and Praised is He) helps to go on Hajj to His House and do the rituals in the required manner will—inn shaa Allah—be included in the words of the Messenger of Allah (peace and blessings of Allah be upon him), “An accepted Hajj brings no less a reward than Paradise.”

Udhiyah(sacrifice)
        One of the righteous deeds that bring a person closer to Allah in these ten days is to slaughter the sacrifice and to look for a good, fat animal and to spend money on it for the sake of Allah (Glorified and Praised is He).
        Let us hasten to make the most of these great days, before the negligent regrets what he did, and before he asks to go back and receives no response.

Source: http://islamqa.info/en/49042

References:
(1) Narrated by AlBukharee, 2/457
(2) Narrated by AlDaarimi, 1/357; its isnad is hasan as stated in AlIrwa, 3/398.
(3) A hadeeth quds states, “Allaah says: ‘All the deeds of the son of Adam are for him, except fasting, which is for Me and I shall reward for it.’” Narrated by AlBukhaari, 1805.
(4) Narrated by AlNasaa’i, 4/205 and by Abu Dawood; classed as saheeh by AlAlbaani in Saheeh Abi Dawood, 2/462.
(5) Narrated by Ahmad, 7/224; its isnad was classed as saheeh by Ahmad Shaakir.