The Islamic Scholars have Divided Wara’ into Three Levels:
1) Refraining from prohibitions; and this applies to all people.
2) Refraining from doubtful matters; and this is practiced by a smaller number of people.
3) Refraining from permissible matters, by doing only those which are necessary for ones survival; and this is practiced only by the Prophets, the steadfast affirmers of truth, the martyrs and the righteous.
Thus, giving up some permissible things which might otherwise cause a person to become heedless of Allah is one of the levels of Wara’. On the other hand, if a person does a permissible act, intending thereby to use it for the sake of Allah, then this permissible act becomes an act of worship which is then added to his record of good deeds; such as sleeping with the intention of having enough power and strength to pray the night prayer, or getting married with the intention of providing for one's future wife, having children, protecting oneself from immorality and increasing the number of Muslims.
The more pious a person becomes, the faster he will pass over the Siraat (i.e., the bridge which is over the Hellfire) and the easier his being held to account will be.
A Muslim must be careful not to come close to the limits of Allah lest he might transgress them, Allah Says (what means): {….These are the limits set by Allah, so do not approach them…..} [Quran 2:187]
Allah also Says (what means): {….These are the limits of Allah, so do not transgress them…..} [Quran 2:229]
These are the limits which one is prohibited from approaching; they refer to the boundary of where the lawful ends and the prohibitions begin, so the verse means do not transgress what Allah has permitted and thereby cross the border into the prohibitions.
A Muslim must give up anything that might lead him into delving into great sins which would cause his destruction, whether this is related to looking, talking, listening, or anything else. In the book of Imam Ahmad the Prophet said: “… Sin is that which creates doubt in you, and which you would not like people to know of.” The Prophet also said: “It is never that you give something up for the Sake of Allah except that Allah will replace it with something better.”
In a great Hadeeth in the book of Imams Bukhari and Muslim the Prophet said: “Both the legal and illegal matters are clear, but in between them there are doubtful dubious matters - and most people have no knowledge regarding them. So whoever saves himself from these doubtful matters saves his religion and his honour; and whoever indulges in these doubtful matters is like a shepherd who grazes his animals near the Hima (i.e., private pasture) of another person, and at any moment he is liable to stray into it. (O people!) Beware! Every king has a Hima, and the Hima of Allah on the earth is what He has forbidden. Beware! There is a piece of flesh in the body, which, if it becomes good (i.e., reformed), then the whole body is reformed, and if it becomes spoilt, then the whole body becomes spoilt - and that (piece of flesh) is the heart.”
Examples of Wara’:
* In the book of Imams Bukhari and Muslim the Prophet told us a wonderful story about two pious men, he said: “A man bought a piece of land from another man, and the buyer found an earthenware jar filled with gold on that land. The buyer said to the seller. 'Take your gold, as I bought only the land from you, and I did not buy the gold.' The former owner of the land said: 'I have sold you the land along with everything in it.' So both of them took their case before another man who asked: 'Do you have children?' One of them replied: ''I have a boy.' The other one said: 'I have a girl.' So the man said (who was judging): 'Marry the girl to the boy, spend the money on both of them, and give the rest of it in charity.'”
* The Prophet would refrain from eating dates whilst he was hungry fearing that they might be from the Zakah fund. In the book of Imams Bukhari and Muslim the Messenger of Allah said: “I would go (home) to my family and find a date lying on the bed and pick it up to eat it, but then throw it away fearing that it might be from the Zakah fund.” So, despite being hungry, he refrained from eating it out of Wara’.
* In the book of Imam Bukhari there is a story proving that Abu Bakr was the most pious person after the Prophet : "A young boy used to work for Abu Bakr and would bring him his food; once he brought a dish of food. Later on, the boy asked Abu Bakr : ‘Do you know where I got this food from?’ He replied: ‘No, where did you get it from?’ The boy replied: ‘I told a man his fortune during my pre-Islamic days, and I was not good at this, but I tricked him (into believing me). So, he met me today and gave me this food because what I had told him (regarding his fortune) came true; so that is what you ate.' Thereupon, Abu Bakr put his finger into his mouth and forced himself to vomit out what he had eaten."
* ‘Umar was distributing clothes to the women of Madeenah and at the end of this distribution there was one garment left which was of better quality than the others, so some of the people around him suggested that he should give it to Umm Kulthoom the daughter of ‘Ali and she was of course also the granddaughter of the Prophet whom 'Umar had married, but he replied: "Umm Saleet is more deserving of it, as she helped us during the battle of Uhud."