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.

(References: Apocalypse Revealed 830)

'To hurt,' as mentioned in Revelation 6:6, signifies violation and profanation.

In Revelation 9:4, this signifies perverting the truths and goods of the church by crafty rationalizations from sensory scientific facts and fallacies.

'To be hurt of the second death,' as mentioned in Revelation 2:11, signifies sinking under evils and falsities from hell.

(References: Apocalypse Explained 9 [4]; Apocalypse Revealed 316)