...which join together in different combinations, varying in terms of closure and compression... In this case the lights shine in a mode of concealment, radiating only as a source. …or opening and unfolding… In the latter case, the lights shine in such a way that the radiation spreads. Sometimes the closure or compression may be in the middle, while the opening may be on the right or the left, and so on.
Opening and closure are signified respectively by the line and the dot… these are the fundamental components of all the letters. The letter Yud is a dot, while the letter Vav is a line. For example the letter Aleph has closure on the right and the left (the two Yuds), and extension in the middle (the diagonal Vav).