यदृच्छालाभतुष्टस्य तेजो विप्रस्य वर्धते ।
तत्प्रशाम्यत्यसन्तोषादम्भसेवाशुशुक्षणिः ॥
yadṛcchā-lābha-tuṣṭasya tejo viprasya vardhate |
tat praśāmyaty asantoṣād ambhasevāśuśukṣaṇiḥ ||
(Śrīmad Bhāgavatam: 8.19.26)
“[Vāmanadeva to Bali Mahārāja:] The potency of a brāhmaṇa who is satisfied with that which is attained of its own accord increases, and that [i.e., that potency] is extinguished because of dissatisfaction like fire by water.”