佛說觀佛三昧海經 3.52

3.52

佛告諸比丘：「汝等先世，於不疑處橫生疑見，於可信處橫生不信。以是罪故，不見諸佛、不聞正法，如我今者現生王宮，我色真正色中最上，汝見赤土。」

The Buddha said to the monks: "In your past lives, where there was no cause for doubt, you groundlessly gave rise to doubtful views; where there was cause for faith, you groundlessly gave rise to disbelief. Due to this sin, you did not see the Buddhas nor hear the correct Dharma. Just as I have now appeared in the royal palace, and my physical form is genuine and supreme among forms, you see red earth."