Sokuzan talks about the practice of "Tonglen", or sending out positivity and receiving negativity while riding the breath, reversing the tendency of ego. He suggests that without a strong awareness practice, taking in negativity may cause more difficulty and instead recommends the practice of "Maitri Bhavana" or extending the intent of loving kindness to others.

https://www.youtube.com/watch?v=dmQ9Mur7Y68

https://www.youtube.com/watch?v=PoC_MBvChiU