Six fingers: eyes, ears, nose, tongue, body and mind.

Six roots and six dusts are collectively called twelve items;

There is a one-to-one correspondence between six roots and six dusts. When six roots are opposed to six dusts, six senses are generated: eye sense, ear sense, nose sense, tongue sense, body sense and consciousness.

Six roots, six dusts and six senses are collectively called eighteen realms.

Touch here refers to the external dust and the touched object. Instead of referring to roots and knowledge;

Buddhism refers to the universal law corresponding to meaning. Which is what we call legal dust. Such as our consciousness, ideas, logic, thinking and so on. Mainly belongs to the category of Italian realm.