A show of envy is an insult to oneself

न शरन्मेघवत्कार्ये
वृथैव घनगर्जितम् ।
परस्यार्थमनर्थं वा
प्रकाशयति नो महान् ॥

- हितोपदेशः

One should not roar in vain like the thundering of autumn clouds (which don't rain). A great person never proclaims the gains or losses of others.

A show of envy is an insult to oneself.