What do you mean by the Four Bodhisattvas? What is the explanation?

According to the 17th Mahayana Sutra of Tantric Buddhism to Tathagata, four methods of bodhisattva transforming all sentient beings are listed, namely: (1) wisdom, in which the Bodhisattva knows the roots of all sentient beings with great wisdom and lets them go free. (2) Huimen, the Bodhisattva preaches profound Buddhism and wonderful righteousness for all beings with great wisdom, so that they can develop their wisdom and know that all Buddhism is empty. (3) Dalagni Gate, Dalagni, will always be righteous. Bodhisattva follows the enlightenment and faith of all beings with the method of all-embracing, so that it can destroy all evil deeds and do all good laws. (4) There is no obstacle to the solution of the door, and the Bodhisattva preaches endless and far-reaching legal meanings for the unimpeded solution of all beings, so that they can get the unobstructed solution. p52 13