Thich Nhat Hanh said this quote
“ Mindful observation is based on the principle of “non-duality”: our feeling is not separate from us or caused merely by something outside us; our feeling is us, and for the moment we are that feeling. We are neither drowned in nor terrorized by the feeling, nor do we reject it. Our attitude of not clinging to or rejecting our feelings is the attitude of letting go[.] ”