This general foundation had to receive its light initially through the mystery of the Line joining with the Residue. First, however, it had to be completed, because this was the whole reason why the Tzimtzum took place – in order to bring into existence a place for evil, so that it could be rectified and ultimately become good. Accordingly the light, which is from the Eyn Sof, blessed be He, must also wait until the vessel is completed, since this is where the root of evil lies.
Only afterwards will it shine in it, and then everything will be complete. Accordingly, at first the light was not joined with the vessels but became hidden above, until the vessels completed their purpose, which is to provide a place for evil to rule and also complete its rule. Its repair will then come, turning everything back to good, and then the light will shine in it.