Chandogya Upanishad 7.15.2

7.15.2

sa yadi pitaraṃ vā mātaraṃ vā bhrātaraṃ vā svasāraṃ vācāryaṃ vā brāhmaṇaṃ vā kiṃcid bhṛśam iva pratyāha \
dhik tvāstv ity evainam āhuḥ \
pitṛhā vai tvam asi mātṛhā vai tvam asi bhrātṛhā vai tvam asi svasṛhā vai tvam asy ācāryahā vai tvam asi brāhmaṇahā vai tvam asīti \\715.2\

2. If one answers harshly, as it were (iva), a father or mother, or brother, or sister, or teacher, or a Brahman, people say to him: “Shame on you! Verily, you are a slayer of your father! Verily, you are a slayer of your mother! Verily, you are a slayer of your brother! Verily, you are a slayer of your sister! Verily, you are a slayer of your teacher! Verily, you are a slayer of a Brahman!”