Abdul Qadir Jilani (ra) ...

There are ten virtues to be practiced 
By those engaged in spiritual struggle and self-examination

If they keep them up and master them by Allah's leave 
They will attain to noble stations


The servant should not swear by Allah,whether truthfully or falsely, deliberately or absentmindedly. If he exercises this kind of self-control and trains his tongue accordingly, it will bring him to the point where he can give up swearing altogether, with or without premeditation. Once he has become accustomed to this, Allah will open a door to His lights, letting him experience the benefit thereof in his heart, and raising him in rank and strength, in his resolve and his patience, in the approbation of his brethren and the esteem of his neighbors, so that all who know him will regard him as a good example, and everyone who sees him will hold him in awe.

He should avoid lying, whether in jest or in earnest. If he practices this self-control and his tongue gets used to being restrained, Allah (Exalted is He) will thereupon expand his feelings and purify his mind. It will be as if he had no knowledge of lying, and when he hears it from another he will reproach and rebuke him for it within himself. If he prays for the person to be rid of it, there will be a reward for him.

He should beware of promising something to someone and then failing to keep his promise. He would do better to stop making promises altogether, so as to gain strength for his task and to keep his sense of purpose, since breach of promise is tantamount to lying. If he acts on this advice, the Lord will open to him the door of liberality and the degree of modesty, and he will be granted love among the truthful and higher esteem in the sight of Allah.

He should avoid cursing anything in the realm of creation, or hurting anything from a mere atom upward. This is one of the moral standards of the pious and the champions of truth. It yields a good result for one who observes it, in that he enjoys Allah's protection in this world, along with the spiritual degrees He has in store for him, and He delivers him from the pitfalls of perdition, keeps him safe from people, blesses him with human compassion, and brings him near to Himself.