Ashtangasamgraha 41.33

41.33

āhārārthaṃ bhayāt pādasparśādativiṣāt krudhaḥ |

pāpavṛttatayā vairāddevarṣiyamacodanāt |

daśanti sarpāsteṣūktaṃ viṣādhikyaṃ yathottaram ||

For food, out of fear, from touch of a foot, from excess of venom, out of wrath, / from an evil disposition, out of enmity, or by the command of gods, sages, or Yama: / snakes bite [for these reasons]; among these, the excess of poison is said to increase in succession.