“Let one not despise what one has received, nor envy the gains of others. The one who envies others does not attain peace of mind in meditation.”
Canonical Pali Original: Salābhaṃ nātimaññeyya, nāññesaṃ pihayaṃ care; Aññesaṃ pihayaṃ bhikkhu, samādhiṃ nādhigacchati.
— Gautam Buddha
The Awakened One, Founder of Dhamma
Pali Canon: Dhammapada 25.365 on cultivating contentment and freedom from jealousy.