This is part of the Tui Shou within Sun Style Martial Arts, the idea is to listen to your opponent through touch only and disrupt their root.
It is difficult at first as you try and use strength instead of feeling.
Standing opposite your partner place a palm on their stomach area they can put a hand covering yours. Try and feel where the body weight is and so push gently to disrupt their root if they counter by moving listen with your touch and alter where you push, do not use force or quick movements just feel.
As you progress you can listen and lead your opponent to disrupt the root, it can be frustrating at first but don’t be put off persevere with this training and your push hands will also improve.