MN62 The Greater Discourse of Advice to Rahula

Material form, feeling, perception, formations and consciousness should be seen as "This is not mine, this I am not, this is not my self".

The elements are, with examples of internal components:

• earth. e.g. skin, bones. 
• water. e.g. blood, sweat, tears, urine
• fire. something eaten or drunk. It warms, ages, and is consumed
• air, e.g. wind in bowels, the breath
• space. e.g. the orifices

The elements can be either internal or external. The internal elements are whatever "belongs to oneself". I have given some examples of internal elements. The external elements are whatever is not internal.

The elements should be seen as what they are: "This is not mine, this I am not, this is not my self".

The Buddha encourages Rahula to develop meditation that is like each of these elements. For example, people throw both clean and dirty things onto the earth, but the earth is not repulsed by this. People wash clean and dirty things in water, but the water, too, is not repulsed by this. And so on for fire, air and space.

He also recommended other meditation:

• loving-kindness. Ill will be abandoned from this
• compassion. Cruelty will be abandoned.
• altruistic joy. Discontent will be abandoned
• equanimity. Aversion will be abandoned
• foulness. Lust will be abandoned
• mindfulness of breathing. 

The Buddha summarises the mindfulness of breathing meditation

• become aware of your breathing
• train to "experience" and "tranquilise" the whole body
• then likewise to rapture
• then mental formation
• mind. This has a few more steps to it. "I shall breathe in experience the mind" and "I shall breathe out experiencing the mind". But you should also train at gladdening, concentrating and liberating the mind.
• contemplate impermanence
• then fading away
• then cessation
• then relinquishment