—whether that other be a prophet, a righteous servant, a mere pebble among the pebbles, or anything else in the created realm. Whoever directs any act of worship to someone other than Allah has committed the gravest offence Allah has forbidden; that is shirk.
Therefore understand the correct definition of tawhid and the correct definition of shirk, for there are people who explain tawhid incorrectly and others who misinterpret shirk.
Some people insist that shirk is limited to violating Allah’s sovereignty in legislation (ḥākimiyyah), a view that has unfortunately become widespread today. Ruling by something other than what Allah has revealed is indeed one form of shirk, termed the shirk of obedience, and there is no doubt that obeying a created being in declaring lawful what Allah has forbidden or declaring unlawful what He has permitted is shirk. Yet there is something even greater than that: worshipping anyone besides Allah by offering sacrifices, making vows, circumambulating, or seeking relief. One must beware of every manifestation of shirk; it is not acceptable to denounce one form while ignoring another that is more serious and more dangerous. Shirk is not to be confined to ḥākimiyyah alone, nor to what is called political shirk. Some even claim that the shirk practiced at graves is a naïve, trivial matter. Such audacity toward Allah! Shirk is the most heinous prohibition laid down by Him; it is to invoke another alongside Him. That is shirk.