What is the ruling on addressing a disbeliever with the terms "O Master" and "O Friend"?

It is not permissible to address a hypocrite or a disbeliever as "Sayyidi" (my master) or "Sayyiduna" (our master), due to the hadith: "Do not call a hypocrite 'Sayyiduna,' for if he is your master, you have angered your Lord." Nor should they be called "Sadiq" (friend), as the Qur'an prohibits befriending and showing affection to disbelievers.

However, addressing someone as "Ya Sayyid al-Fulanin" (O master of so-and-so) is permissible, in the sense of their leader. It is also permissible to refer to a Muslim as "Sayyid" without the definite article "al-" (the), such as the Prophet Muhammad's statement about Al-Hasan: "Indeed, this son of mine is a Sayyid."

It is disliked to address a Muslim as "Ya Sayyidi" or "Ya Sayyiduna" because when the Prophet Muhammad was told, "You are our Sayyid," he replied: "The Sayyid is Allah, the Blessed and Exalted." This is also because it might cause conceit. It is preferred to use names and kunyas (honorifics).

It is not permissible to use the word "Al-Sayyid" with the definite article "al-" for anyone, even if they are Muslim, because "Al-Sayyid" is Allah.