In his description of the induction of the first state of concentration, Gautama spoke of how a person:
… steeps, drenches, fills and suffuses this body with zest and ease, born of solitude, so that there is not one particle of the body that is not pervaded by this lone-born zest and ease. (1)
In my practice, I make use of some advice Shunryu Suzuki gave, to find “zest and ease”:
If you think that you have some difficulty in some part of your body, then the rest of the body should help the part that is in difficulty. You are not having difficulty with some part of your body, but the part of the body is having difficulty: for example, your mudra is having difficulty. Your whole body should help your mudra do zazen. (2)
I look to my whole body for help with relaxation at the location of my awareness. If my entire body is engaged in the relaxation of the muscles around the “heart-mind”, as the Chinese describe it, then I experience something like zest and ease.
In the same way that the whole body can provide relaxation to the location of awareness, the multiplicity of the senses can provide calm, and in my experience calm at the location of the heart-mind results in an expansive equanimity.
To be clear, the location of awareness or “heart-mind” can shift and move, as Suzuki pointed out:
Sometimes when you think that you are doing zazen with an imperturbable mind, you ignore the body, but it is also necessary to have the opposite understanding at the same time. Your body is practicing zazen in imperturbability while your mind is moving. (2)
1) AN III 25-28, Pali Text Society Vol. III pg 18-19
2) “Whole-Body Zazen”, lecture by Shunryu Suzuki at Tassajara, June 28, 1970 (edited by Bill Redican, http://www.cuke.com/Cucumber%20Project/lectures/wholebodyzazen.html).