Explanation
On the authority Abi Ab'dillahi al-Nu'man ibn Basheer (ra) who said: I heard the Messenger of Allah (peace be upon him) say: "That which is lawful is clear and that which is unlawful is clear and between the two of them are doubtful [or ambiguous] matters about which not many people are knowledgeable. Thus, he who avoids these doubtful matters certainly clears himself in regard to his religion and his honor. But he who falls into the doubtful matters falls into that which is unlawful like the shepherd who pastures around a sanctuary, all but grazing therein. Verily every king has a sanctuary and Allah's sanctuary is His prohibition. In the body there is a morsel of flesh which, if it be sound, all the body is sound and which, if it be diseased, all the body is diseased. This part of the body is the heart"
Commentary
Abu Dawud said Islam revolves around 4 ahadith, with this being one of them
Upon hearing that halal and haram are clear, we should thank Allah as He has made it easy for us
The scholars say that the halal and haram mentioned here are the evidently clear halal and haram matters
There are many reasons why a matter may be doubtful, examples of such include:
An action being doubtful due to the person not understanding the ruling properly, therefore the deficiency is not in the ruling itself, but in the understanding of that person. In this example, the action is not doubtful to everyone, as it would be clear to the scholars.
Not knowing the background information behind the matter e.g. you hunt a bird by shooting it, but when you arrive, you see the bird dead in a pond and you are unsure if it died from being shot or it died from drowning (which would make it haram). In this example, the matter is doubtful to everyone as there is no way of ascertaining the truth.
A doubtful action which leads to a haram e.g. going out with friends who you know may lead you to sin. In this example, doing the action will not necessarily be haram, but due to the risk associated with it, you should avoid it.
Having ill-thoughts of someone is haram, but if someone always follows the doubtful matters e.g. always associates themselves with bad people, or is often seen in unpleasant places, then it isn't haram to think that this person is doing haram as they have brought it upon themselves by not leaving the doubtful matters
The hadith finished off by talking about the heart, because if you go near the boundary, you will end up with a corrupt heart
Signs of a pure heart:
Considering oneself a resident of the hereafter
Continuously feeling upset until you repent from the sin
Feeling upset if you forget to read your daily recitation/dhikr as if you had lost something from the dunya
Finding greatest pleasure in worshipping Allah
When you begin prayer, everything from the dunya leaves your heart
Your only concerns and worries are with pleasing Allah
You are more stingy with wasting time than a stingy man with his wealth
You are very concerned with the correctness of your actions
Signs of a dead heart:
Feeling no pain/hurt once doing a sin
Finding pleasure in sinning and peace of mind after it
Looking into less important matters and prioritising them over important ones
Not finding comfort when around the righteous but finding comfort with time wasters
You are easily led into misconceptions and doubt, and you like to debate these issues
You are not affected by reminders/talks
