This hadith is one of the hadiths which describes the central tenets of Islam. It is a very important hadith, and one of the principal foundations of Islamic teaching. It is an example of the concise speech of the Prophet (blessings and peace of Allah be upon him), as in it he urges the Muslims to err on the side of caution and avoid doubtful matters concerning which there is no clear reference in the religious texts. He explained that what is halal is clear and evident; it is everything for which there is no evidence that it is prohibited in the Qur’an, Sunnah, scholarly consensus (ijma‘) or analogy (qiyas), because the basic principle is that things are permissible [unless there is evidence to the contrary]. Similarly, what is haram is also clear and evident; it is everything for which there is evidence that it is prohibited, whether that evidence is from the Qur’an, the Sunnah or scholarly consensus. He stated that between what is halal and what is haram, there is a third category, which is doubtful matters. These are matters concerning which there is no clear ruling as to whether it is halal or haram, so many people are not able to know the ruling on these matters. This includes all doubtful and ambiguous matters, such as wealth from dubious sources, or wealth that is mixed with riba, or other kinds of unlawful wealth. As for cases when one is certain that this wealth has definitely been acquired through riba, then it is one hundred percent haram, beyond any shadow of a doubt, and it cannot be regarded as doubtful or dubious. Then the Prophet (blessings and peace of Allah be upon him) explained that whoever avoids doubtful matters is erring on the side of caution, so his faith will be protected from falling short, and his honour will be protected from any aspersions, criticism or bad reputation. As for the one who falls into doubtful matters and has the audacity to accept them, he is exposing himself to danger, for he will soon fall into that which is haram, like a shepherd who grazes his flock around a sanctuary, which is the land that the king sets aside for his own flocks, and warns anyone who grazes his flocks there without his permission that he will face a severe punishment. If a shepherd grazes his sheep around the land that the king has set aside for himself and designated for his personal use, his flock may enter the sanctuary, in which case he will deserve the punishment of the ruler. By the same token, the one who is careless about doubtful matters is in danger, because those matters may be haram, and he may fall into them, or he may become careless about doubtful matters, and that leads to him becoming negligent and careless in general, so he begins to fall into haram matters deliberately. Falling into dubious matters may lead to falling into minor sins, and falling into minor sins may lead to falling into major sins. We ask Allah to keep us safe and sound. Then the Prophet (blessings and peace of Allah be upon him) said: “Indeed, every king has a sanctuary and, indeed, the sanctuary of Allah on His earth is His sacred limits.” In other words, the sanctuary of Allah is the sins that He has prohibited to His slaves; whoever enters His sanctuary by committing any of those sins is doomed, and whoever comes close to it by doing doubtful things is in danger. Then the Prophet (blessings and peace of Allah be upon him) spoke a comprehensive word which explains what causes the sons of Adam to behave in a righteous or corrupt manner, which is that the basis of physical wellbeing has to do with the soundness or otherwise of the heart. If the heart is (spiritually) sound, then the person’s intentions will only seek what is right and proper, and all his physical faculties will be sound, and he will not be prompted to do anything except obey Allah and avoid His wrath. Thus he will be content with what is halal and have no need of what is haram. But if the heart is (spiritually) corrupt, then the person’s intentions will be corrupt, and all his physical faculties will be corrupt, and he will be prompted to disobey Allah (may He be glorified in exalted) and to do that which incurs His wrath. He will not be content with what is halal; rather he will hasten to seek that which is haram, in accordance with what his heart desires and the extent to which it drifts away from the truth..