This quote is from Master Hsuan Hua‘s commentary on the Medicine Master Sūtra.

Fundamentally, our tempers do not come from the food we eat, nor from heaven or earth, nor from the weather. They come from our own ignorance. Ignorance comes from selfishness, as do afflictions, indirectly. We have so much anger and affliction simply because we are afraid to suffer a loss. Not wanting to take a loss, we get mad and fight. If we did not fight, were not greedy, did not seek anything, were not selfish, and did not want to benefit ourselves, we would have no anger.

Among the Bodhisattvas, Guanyin Bodhisattva (Avalokiteśvara, Kannon) has great compassion, and if you recite his name, he will relieve your suffering and pain. He has great affinities with all beings. If you wish to strengthen your ties with Guanyin Bodhisattva, recite his name more often and let your light blend with his.

Earth Store Bodhisattva (Kṣitigarbha, Jizo) has great vows. He cannot bear to see any living being in suffering. If we recite his name, he will help us to quickly attain Buddhahood with his awe-inspiring spiritual power. Did these two Bodhisattvas place advertisements in the sūtras to promote themselves? No. The Buddha, who always speaks the truth, personally praised them and told us about their great compassion and great vows.