Is the fundamental principle concerning acts of worship prohibition until evidence is presented [to permit them], and the fundamental principle concerning worldly dealings permissibility until evidence is presented to prohibit them? And can this rule be applied to customs and traditions, such that a pure custom is permissible, while an act of worship that involves seeking nearness [to God] is not permissible?

The fundamental principle regarding acts of worship is prohibition, except for what Allah has legislated. The fundamental principle regarding customs is permissibility, except for what Allah has forbidden. Allah reproached the polytheists for associating with Him that for which He had sent down no authority, and for prohibiting what Allah had not forbidden to them. Shirk (definition) (associating partners with Allah) includes every act of worship for which Allah has not given permission. For this reason, the origin of misguidance on earth stemmed from adopting a religion that Allah did not legislate or prohibiting what Allah did not forbid.

If a scholar were asked about a permissible act, such as walking between two mountains or uncovering one's head, he would answer with permissibility. But if he were told that it was being done as an act of worship, he would declare it forbidden. If he were asked about standing in the sun for a permissible purpose, he would say it is permissible, but if it were done as an act of worship, it would be an abomination, as in the hadith (definition) of Abu Isra'il, whom the Prophet (peace be upon him) commanded to sit, speak, seek shade, and complete his fast. Similarly, entering houses from their backs, if done as an act of worship, is an abomination and an innovation.

Indeed, innovation is more beloved to Iblis than disobedience, because the disobedient person knows he is disobedient and repents, whereas the innovator considers what he does to be an act of obedience, so he does not repent. Whoever does something considering it a path to Allah, he takes it as a religion, and such people are astray by the consensus of Muslim scholars.

This rule judges people's traditions and customs: whatever of them is done as an act of religiosity, closeness to Allah, and worship, the default is prohibition unless there is evidence [for its permissibility], such as one who worships by circumambulating graves. And whatever is done as a custom and not as an act of worship, the default is permissibility unless there is evidence for prohibition, such as visiting each other after Fajr prayer.