Dhikr i.e. mental 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.
Obviously dhikr does not benefit Allah, Who has no need of in the benefit is for Allah’s bondsmen since dhikr strengthens the bond between Allah and His bondsmen, 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 submitted to the eternally blessed Prophet ‘O Messenger of Allah! Good deeds are many and I do not have the strength to perform all of them. So please tell vie 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 Fad1 a1 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 Judgment” (Abu Da’ud)
That’s why a hadith tells us to recite the following worlds at the end of every meeting or this atones for the shortcomings of the meeting.
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 Qibla 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 Qibla; 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 Maulana Muhammad Dhakariyya.
2. Dhikr Allah by Maulana Mufti Muhammad Shafi.
3. Ma’mulat-e-Yaumiyah by Dr. Abdul Hai Arifi