Dhikr of Allah
Dhikr i.e. nimtal or verbal remembrance of Allah is so consoling, pleasant and easy form of worship that one can perform it continuously at all times and with great benefit. Allah has enjoined His Dhikr in the Quran in the following words:
Obviously dhikr does not benefit Allah, Who has no need of it; the benefit is for Allah's bondsmen since dhikr strengthens the bond between Allah and His bondsmen. It is food for the soul which invigorates it. And with an invigorated soul it becomes easy to overcome one's base instincts and to vanquish the Devil. Thus one is able more easily to avoid sins and the good deeds increase.
Someone asked our eternally blessed Prophet "Which worship is highest in the Eyes of Allah and which shall be reckoned weightiest on the Day of Judgement?" The Prophet replied "Dhikr of Allah" (Jami'al Usul, p. 475 Vol. 4)
A companion once submited to the eternally blessed Prophet "O Messenger of Allah! Good deeds are many and I do not save the strength to perform all of them. So please tell me one thing that I may always remember. Please do not tell me many things as I would forget them." The Holy Prophet said "Your tongue should be wet with dhikr of Allah". (Jami Tirmidhi, Dawat Bab Fadl al Dhikr).
Abu Musa Ash'ari has been quoted as follows: The eternally blessed Prophet said "A house wherein Allah is remembered and a house wherein He is not remembered are like living and dead bodies" (Bukhari and Muslim).
Another hadith quotes our Prophet as follows: "People who leave a meeting or conclave without mentioning and remembering Allah are like those who get off from a dead ass, and such a meeting they would repent (for time misspent) on the Day of Judgement" (Abu Da'ud).
That's why a hadith tells us to recite the following words at the end of every meeting or conclave.
In spite of the great merits of dhikr. Allah has made it very easy. There are no preconditions attached to it. If someone performs ablution and then sits facing qiblah and performs dhikr it is all for the best. But if there is no time or occasion for it then one can perform dhikr while engaged in other works, even ablution is not required and dhikr is permitted even when unclean after coition or while menstruating. However one should not perform it verbally when unclothed or when in some unclean place like lavatory. However even there dhikr can be done without intoning or moving the tongue. Thus the merits of this worship can be reaped at all times without any difficulty. However it is appropriate to fix a particular time in the night or the day when one can perform dhikr after ablution and facing the qiblah; dhikr at other times would be an added boon.
For special dhikr the following books may be consulted.
1. Fada'il-al-Dhikr by Shaikh al Hadith Hadrat Mawlana Muhanumd Dhakariyya
2. Dhikr Allah by Mawlana Mufti Muhammad Shafi
3. Ma'mulat-e-Yaumiyah by Dr. Abdul Hai Arifi
However some brief adhkar are given below which should be recited continuously.
1. Hadith quotes our eternally blessed Prophet as saying that
"The following four phrases are most pleasing to Allah." (Sahih Muslim)
2. Hadith tells us that two phrases most pleasing to Al Rahman are light on the tongue but view weighty on the Day of Judgement (Bukhari Muslim):
3. Hadith tells us to recite because these words are among the treasures of paradise (Mishkat)
4. Hadith tells us that if one recites these words in the morning he gets merit equivalent to freeing of ten slaves from among the progeny of Prophet of Islam, he gets ten good deeds recorded in his name, his ten sins are pardoned he is elevated by ten stages and is protected against the Devil till evening. And if he recites these words in the evening; he gets the same reward till morning (Abu Da'ud).