A tutorial series by guest poster, Mick Frankel
Part Two — the Double Letters
We’ve looked at the three Hebrew letters that Sefer Yetziroh calls “Mother Letters” or “Primary Letters”. These are א מ and שׁ.
Next, Sefer Yetziroh mentions a group of seven letters that are called “Double Letters”.
There are four letters that change their sound according to whether they have a dot in the middle or not. The version with the dot has a harder sound.