Question: Rabbi, Why is the Torah Scroll written with 42 lines per page?
Answer: Hi! Thanks for your interesting question. Sometimes you find that things can be done in many different ways. Over the course of time, sometimes we settle on a particular way, not because it has to be that way, but because it ensures better quality control if things are standardized.
So too here. Maimonides (Laws of the Torah Scroll: 7:10) gives a range on the number of lines per page allowable – anywhere between 48 and 60 is best. He says that he himself wrote a Torah Scroll with 51 lines per page (ibid. 9:10). Other sources give other numbers of lines. For instance, the Shitah Mekubetzes in the Talmud Menachos gives 42 lines per pages, corresponding to the number of journeys of Israel in the desert. And that one is our current custom.
These days, pretty much all Torah Scrolls are written from an identical template. Same lines, same words in the same places. It’s just easier that way.
Best wishes,
Michoel Reach