Ibni ’Âbidîn ‘rahmatullâhi ’alaih’ in explaining the makrûhs of namâz says: “Things which disbelievers do and use are of two groups: The first group are things which they do as customs, that is, things which each nation, each country does as its customs. Out of these, doing or using things that are not harâm and that are useful is never a sin. [Wearing trousers, fez, different types of shoes, using spoons and forks, eating meals at a table, putting each person’s meal in a dish in front of him, cutting the bread in slices with a knife, and using various tools and gadgets are all behaviours concerning customs and are mubâh. It is not a bid’at or a sin to use them.] Rasûlullah wore shoes specially made for priests.” Among them, doing or using the ones that are unpleasant and loathsome and which are not useful is harâm.
But, after two Muslims use them, they become (Islamic customs) and are not harâm for the third Muslim who uses them. The first and second Muslims become sinful, but not the others. In the book Qâmûs-ul-â’lam, in the passage giving information about Timurtaş Pâsha, it is written: “Timurtaş Pâsha is the person who designed the color of the Ottoman Banner, and also the shape of today’s Turkish flag with its crescent and star. He also gave today’s red colour to the fez, which had been white up until that time.” The colour of the Abbâsî State’s flag was black. It was changed to white during the time of khalifa Ma’mûn. As it can be seen, the fez was not taken from the Hungarian people, but rather, it was developed by the Turks. It is written in Birgivî Wasiyyetnâmesi, “The second group of things which disbelievers use are things which are symptoms of disbelief, symptoms of denying and disbelieving the Ahkâm-iislâmiyya and Islam, and it is wâjib for us to abhor them. A person who does or uses them becomes a disbeliever. They cannot be used unless one is intimidated with death or with the amputation of one’s limbs or other treatments causing these results such as severe thrashing or imprisonment or extortion of all one’s property. Also, he who does or uses a commonly known one of them without knowing or as a joke in order to make people laugh, becomes a disbeliever. For example, it is kufr to wear (or use) things specially worn or used by priests during their worship. This is called Kufr-i hukmî.”
It is written in the basic books of Fiqh by Islamic scholars that to wear the ‘things that are peculiar to disbelievers is kufr. See Ibn-i ’Âbidîn, Vol. V, page 481. The enemies of Islam, in order to deceive Muslims, try to hide the fact that it is kufr to adopt the customs of disbelievers and to celebrate their festivals. They call these customs ‘Islamic customs’ and these days ‘sacred days’. They represent the Noel (Christmas), which was introduced into Christianity by Constantine the Great, and Nawruz, which was invented by Jamshîd, as a national celebration; and they want Muslims to accept the same things. Young and innocent Muslims should not believe their lies. They should learn the truth by asking those sincere Muslims whom they trust, their relatives who perform namâz, and those family friends who know their religion.
Today, no matter where in the world, not to know what is îmân and what is kufr or how to perform ’ibâdats correctly is inexcusable. He who is deceived because he does not know his faith will not be saved from Hell. Today, Allâhu ta’âlâ has made His religion known everywhere in the world, and He has made learning îmân, the fards, the harâms, the halâls, and beautiful morals very easy. Everybody should learn as much as necessary and this is a fard. One who does not learn them is deemed to have disobeyed the fard. But a person who says that there is no need to learn them or who attaches no importance to them becomes a disbeliever.
 Muhammad Birgivî Bey’s father is Alî. He was born in Balıkesir in 928 and died of the plague in 981 A.H. His works, Vasiyyetnâme, Tarîqat, Awâmil, Izhâr and others, are very valuable.