Observe the courtesy of supplication. Consider the One on whom you call, how you call on Him and why you call; affirm the immensity and magnificence of Allah. Look with your heart at how He knows what is in your conscience, how He sees your secret being and whatever has occurred and will occur in it, both true and false. Learn the paths to your salvation and destruction, so that you do not call upon Allah for something which perhaps contains your destruction, but which you suppose to contain your salvation. Allah said,
Man prays for evil as he ought to pray for good, and man is ever hasty. (17:11)
Reflect about what you ask for and why you are asking: supplication should be a total response to the Truth on your part, and a melting of the heart in contemplation of its Lord. It is to abandon all choices and to surrender all matters, both outward and inward, to Allah. If the preconditions of the supplication are not met, then do not look for fulfillment, for He knows what is secret and what is hidden; you might ask Him for something when He knows that you conceal the opposite of it.
One of the companions said to the others, 'You are waiting for rain, and I am waiting for stones.' Know that if Allah had not commanded us to call on Him, He would nevertheless have favoured us with an answer immediately after we finished the prayer. How, then, is His favour, given the fact that He has guaranteed that answer to whoever fulfils the conditions of the prayer?
The Messenger of Allah was asked about the most powerful name of Allah: he said, 'Every name of Allah is most powerful.'
Free your heart from all that is other-than-Him, and call on Him by whatever name you like. In reality Allah does not have one name rather than another: He is Allah, the One, the Almighty.
The Holy Prophet said, 'Allah does not answer the supplication of a heedless heart.' When one of you wants His Lord to give to him whatever he asks of Him, he should renounce all people, putting his hope in Allah alone. When Allah sees that in his heart, He will give him whatever he asks.
When you have established the preconditions of supplication which I have mentioned, and have become sincere in your innermost being for His sake, then rejoice in the good news that one of three things will happen: either He will hasten to give you what you have asked for, or He will store up something better for you, or He will avert from you an affliction which would have destroyed you had He sent it. The Holy Prophet reported that Allah said, 'If anyone is distracted from asking Me by his own remembrance of Me, I will give him better than what I give to those who ask.'
I called on Allah once and He answered me. I forgot the need because of the fact that when He answers a supplication, His bestowal is far greater and more sublime than what the bondsman desires from Him, even if it be the Garden and its eternal blessings. This is understood only by lovers who act, gnostics, the elite and the select of Allah.