The loins, as in Ezekiel 29:7, signify the marriage of truth and good. In general, loins signify love, and when referring to the Lord, divine love. They can also signify the interiors of conjugial love. In Isaiah 11:5, they signify people in the divine good of love, and reins signify people in love towards their neighbor.

(Odkazy: Apocalypse Revealed 830)

In Matthew 12:31-32, this signifies to speak against the literal sense of the Word, or the divine truth as it is on earth; while to speak against the Holy Spirit is to utter blasphemies against the Divine Truth as it is in the Lord, or in heaven. (Apocalypse Explained 778[3])