Dorje Senge (Diamond Lion) lived from (1054-1123) and is the author of one of the most famous buddhist texts for developing a good heart (lojong) called the Eight Verses. It’s full of very practical advice for being a kinder and more compassionate person. Diamond Lion was one of the Kadampas, who were the first generation Buddhists in Tibet. Lojong texts for developing a good heart were very popular amongst the Kadampas.
The text of the Wheel of Knives describes how bodhisattvas in the vicious circle of life are like peacocks who actually find poisonous plants more nutritious than medicinal ones. The idea is that the bodhisattvas can transform inner afflictions and outer difficult situations into precious opportunities for personal practice and helping others. According to the text, each unpleasant thing or event that ever happens to us is a result of “what goes around comes around”: the things we have done to others are returning back to us like a wheel of knives.