在顯教，觀六大之空不淨也。在密教，觀六大之圓融無礙也。嘉祥仁王經五曰：「作六大觀，四大空識也。」
Meditation on the six elements; in the exoteric cult, that they are unreal and unclean; in the esoteric cult, that the Buddha and human elements are of the same substance and interchangeable, see above.
一六大觀 觀地、水、火、風、空、識等六大。此有顯、密之別，顯教觀六大之空不淨，密教則觀其圓融無礙。p1638
觀察六大的行法，在顯教是觀察六大之空與不淨，在密教是觀察六大之圓融無礙。