I've asked this on the Islam SE about the ancient Quran, because they may know based on the detailed writings of the prophets and such perhaps some rules which could be insightful. But I wanted to ask here a more broad version because in terms of Linguistics, this could apply cross-culturally focusing on Arabic Orthography's use.
My question is, how do you break words across lines in the Arabic script? What is acceptable practice in various languages, specifically the early Arabic of the Quran (Kufic script), but also modern Arabic, Urdu, Farsi/Dari (Persian), etc. How do you split a word into two pieces, essentially, using the Arabic script?