I shared this with a class last semester in regards to how fearful and respectful the Jews were of the name of God. They would copy the text not word by word, but letter by letter. There could be no erasures. If a mistake was made, the entire scroll was thrown away and the scribe had to begin again from the beginning. When they came to the word El for the name of God, they would wash their pen, take a bath, change their cloths, and dip the pen in fresh ink and write YHVH. They did this because they felt that no man was worthy to pronounce the name of God. We still are not sure how YHVH is pronounced because there are no vowels present. After the insertion of vowels, we now pronounce it as "Yahweh".