Ideas:

1. I think that the right part of this glyph should be seen as a growing plant, a sprout. It seems reasonable to indicate the first appearance of the moon after its period of darkness (or hiding) as a sprout. We know that growth will come.

2. The general form of this sign of coming growth reminds me of my granddaughter Clara's opinion about there being a 'knife' in the right part of the glyph beginning Sunday:

I think there is a structural similarity between these two types of glyphs, where however the variant of command in Sunday is the fullgrown sort.