《礼记·内则》
如果犯颜苦谏招致父母大怒，把自己打得皮破血流，那也不敢生气埋怨，而是更加恭敬更加孝顺。
父母怒、不说，而挞之流血，不敢疾怨，起敬起孝。
If suffering makes their parents angry and beat themselves into a bloody mess, then they dare not get angry or complain, but are more respectful and filial.