A human being can be compared to a harnessing of three horses, which Russians call ‘troïka’. These three horses are symbolically our three bodies – physical, astral and mental – which we must guide all at the same time. They each have a different color: the physical horse is red, the astral horse – the heart – is green and the mental horse – the intellect – is yellow. In order for the three horses to be obedient and to walk in step together, we must hold the reins firmly, that is to say, establish a contact with them with a subtle and etheric link: the will-power. And we must also know the nature of each horse in order to control it. The physical horse needs frugality in food and drink, as well as exercise so as to develop its flexibility. The astral horse is tamed with purity, kindness and love. Lastly, the mental horse needs us to insist on attention, vigilance and lucidity. It is on these three conditions that our horses will not throw us and will take us only where we want to go.
Omraam Mikhael Aivanhov Daily Meditations