During a wedding that took place last night, the rabbi Moshe Chaim Lau performed the chuppah and kiddushin. But suddenly, towards the end of writing the ketubah, the rabbi suddenly turned to those around him and asked that they bring him... salt of life.
The salt was quickly brought to the table, without anyone understanding: Why is salt needed for writing the ketubah?
But then the rabbi took the saltpeter and used it as a ruler to fill in the lines in the empty spaces in the ketubah, while He explains to those wondering around him: "The ketubah is the most precious document there is, binding and connecting the couple, and if everything in a wedding is perfect to the point where one person has found their partner, the ketubah must also be perfect and the lines in it must be straight as a ruler and not carelessly drawn.".
Watch.