Concerning the types of worship to be performed during these ten days: one must understand that these days are a great blessing from Allaah to His slave, which is appreciated properly by the actively righteous. It is the Muslim’s duty to appreciate this blessing and make the most of the opportunity, by devoting these ten days to paying more attention to striving hard in worship. Among His blessings to His slaves, Allaah has given us many ways in which to do good and worship Him, so that the Muslim may be constantly active and consistent in his worship of his Lord.
1. Fasting. It is Sunnah to fast on the ninth day of Dhu’l-Hijjah, because the Prophet (peace and blessings of Allah be upon him) urged us to do good deeds during this time, and fasting is one of the best of deeds.
2. Takbeer. It is Sunnah to say Takbeer (“Allahu akbar”), Tahmeed (“Al-hamdu Lillaah“), Tahleel (“La ilaha ill-Allah“) and Tasbeeh (“Subhaan Allah“) during the first ten days of Dhu’l-Hijjah, and to say it loudly in the mosque, the home, the street and every place where it is permitted to remember Allah and mention His name out loud, as an act of worship and as a proclamation of the greatness of Allah, may He be exalted. Men should recite these phrases out loud, and women should recite them quietly.
Takbeer at this time is an aspect of the Sunnah that has been forgotten, especially during the early part of this period, so much so that one hardly ever hears Takbeer, except from a few people. This Takbeer should be pronounced loudly, in order to revive the Sunnah and as a reminder to the negligent. There is sound evidence that Ibn ‘Umar and Abu Hurayrah (may Allaah be pleased with them) used to go out in the marketplace during the first ten days of Dhu’l-Hijjah, reciting Takbeer, and the people would recite Takbeer when they heard them. The idea behind reminding the people to recite Takbeer is that each one should recite it individually, not in unison, as there is no basis in Sharee’ah for doing this.
Reviving aspects of the Sunnah that have been virtually forgotten is a deed that will bring an immense reward, as is indicated by the words of the Prophet (peace and blessings of Allaah be upon him): “Whoever revives an aspect of my Sunnah that is forgotten after my death, he will have a reward equivalent to that of the people who follow him, without it detracting in the least from their reward.” (Reported by al-Tirmidhi, 7/443; this is a hasan hadeeth).
3. Doing more good deeds in general, because good deeds are beloved by Allah and will bring a great reward from Him. Whoever is not able to go to Hajj should occupy himself at this blessed time by worshipping Allah, praying (salaat), reading Qur’an, remembering Allah, making supplication (du’aa’), giving charity, honoring his parents, upholding the ties of kinship, enjoining what is good and forbidding what is evil, and other good deeds and acts of worship.
4. Sincere repentance. One of the most important things to do during these ten days is to repent sincerely to Allah and to give up all kinds of disobedience and sin.
Repentance means coming back to Allaah and foregoing all the deeds, open and secret, that He dislikes, out of regret for what has passed, giving it up immediately and being determined never to return to it, but to adhere firmly to the Truth by doing what Allaah loves.
If a Muslim commits a sin, he must hasten to repent at once, without delay, firstly because he does not know when he will die, and secondly because one evil deed leads to another.
Repentance at special times is very important because in most cases people’s thoughts turn towards worship at these times, and they are keen to do good, which leads to them recognizing their sins and feeling regret for the past. Repentance is obligatory at all times, but when the Muslim combines sincere repentance with good deeds during the days of most virtue, this is a sign of success, in sha Allaah. Allaah says (interpretation of the meaning): “But as for him who repented, believed and did righteous deeds, then he will be among those who are successful.” [al-Qasas 28:67]
5. Sacrifice. One of the good deeds that will bring a person closer to Allah during these ten days is offering a sacrifice, by choosing a high-quality animal and fattening it, spending money for the sake of Allah.