Returning light (Kabbalah)

This is the light that is not received in the fourth level. That is, its special function is to fill the fourth level, which, however, does not receive the light, on account of the partition that blocks and rebuffs it. This action is called fusion through collision (see Histaklut Penimit, v. 2, section 22, s.v., “ve-hineh”). Likewise, every receiving vessel in the partzufim, from the constriction (tzimtzum) and onwards, is drawn from this returning light, which serves for them in place of the fourth level in Ein Sof. V. 2, Histaklut Penimit, 79 (Talmud Eser Sefirot, v. 2, Q & A 2).