Menachot 31 – How to Repair a Torn Torah Scroll

If the margin of a Torah scroll tore and the tear extends two lines into the writing, one can sew it, and the scroll is still valid. If, however, it extends three lines into the writing, he should not sew it; rather, he should replace the entire sheet. And that which we said that three lines should not be sewn is only true of an old parchment, but with the new parchment it is not a problem. “Old” does not mean literally old, but one that was treated with gallnut juice, and “new” means one not treated with gallnut juice. Some explain it to mean the opposite: a “new” parchment is one treated with gallnut juice, for this makes the parchment strong, and the seam will hold. If one remembers that gallnut juice is a prerequisite for a Torah scroll anyway, the explanation becomes even more complex.

Sewing the tear should be done with sinews, the same material used for sewing the sheets together, and not with threads. The custom, however, is to sew with silk threads, which leads to further study and to the interpretation of the above rule in a different way.

Art: Vincent van Gogh - Woman Sewing