首楞嚴義疏注經 8.361

8.361

「阿難！一者婬習交接，發於相磨，研磨不休，如是故有大猛火光於中發動。如人以手自相摩觸，煖相現前。」

"Ānanda, the first is that the habit of lust involves mutual engagement, arising from mutual rubbing. When the rubbing continues unceasingly, a great fierce blaze of fire is stirred into motion within. Just as when a person rubs their hands together, the tactile sensation of warmth appears before them."