For example, in the first partzuf of Adam Kadmon, whose partition has all five levels of its opacity, that is, up to and including the fourth level, the beating of the surrounding light on the partition of the body purifies the opacity of the fourth level entirely without leaving even a trace of that opacity. Only the traces of the opacity of the third level and upward remain in the partition. Therefore, when that partition is incorporated into the head, where it undergoes the fusion through collision where the supernal light impacts against the opacity that remains in trace amounts from the body, the fusion through collision takes place only through the light beating against the third level of the opacity in the partition, as the traces of opacity of the fourth level are gone and are no longer there.