दुर्जनेन समं सख्यं वैरं चापि न कारयेत् ।
उष्णो दहति चाङ्गारः शीतो कृष्णायते करम् ॥
durjanena samaṁ sakhyaṁ vairaṁ cāpi na kārayet |
uṣṇo dahati cāṅgāraḥ śīto kṛṣṇāyate karam ||
(Hitopadeśa: 3.81)
“Make neither friendship nor enmity with a wicked person, who is comparable to a piece of coal, which when hot burns your hand and when cold turns it black.”