"… languages were written on a tablet of stone using a chisel. Since most people are naturally right-handed, they would hold a hammer with the right hand and a chisel with the left. … That’s why you find most older languages (such as Arabic, Hebrew and Farsi) written from right to left.
When ink was invented, … writing from left to right became more preferable in many parts of the world since this method avoided smudging ink."
Source: https://www.writingbeginner.com/are-arabic-writers-left-handed/