What are the six in SN 1.70?

The sutta quoted below has a riddle about the six. What are the six? And why? What is the message of the sutta? SN 1.70 translated by Bhikkhu Bodhi: > “In what has the world arisen? > In what does it form intimacy? > By clinging to what is the world > Harassed in regard to what?” > > “In six has the world arisen; > In six it forms intimacy; > By clinging to six the world > Is harassed in regard to six.”