Happy [are] those to whom the love of their Master cleaves; there is no limit to their portion in the other world. Many are the abodes of the righteous in the other world, one above another, and highest of all that of those to whom was attached the love of their Master, for their abode is linked with the palace that surpasses all, the Holy One, blessed be He, being crowned in this one. This Palace is called Love, and it is established for the sake of love. So it is too with the Holy Name, the forms of the letters of which are linked together, so that the whole is called “love”; wherefore he who loves his Master is linked to that Love. Hence it is written, “And thou shalt love the Lord thy God”.
Zohar, Chelek Gimmel 267b, Soncino Translation