How can Persian be written in Arabic script when it isn’t a Semitic language?

I am often asked how Persian can be written using Arabic script when it is not a Semitic language.

It might surprise you to learn that the majority of languages that use the Arabic writing system are not Semitic languages. Furthermore, most Semitic languages are not written using Arabic script. In fact, Arabic is the primary Semitic language that uses the Arabic script.

Persian, Urdu, Pashto, and Kurdish all use the Arabic alphabet but are Indo-European languages.

Malay is written with the Latin alphabet, but also with a modified form of Arabic script known as Jawi. Malay is in the Austronesian language family.

Almost all languages in the Turkic language family have historically used the Arabic alphabet.

Various languages in Africa, including Swahili which is a member of the Niger-Congo language family also used the Arabic alphabet.

It might seem that Semitic languages are an outlier when it comes to using the Arabic language family. After all, Hebrew, Syriac (Aramaic), Amharic and Tigray, all members of the Semitic language family all have their own alphabets.