Bhagavad Gita · 2.70

आपूर्यमाणमचलप्रतिष्ठं समुद्रमापः प्रविशन्ति यद्वत्।तद्वत्कामा यं प्रविशन्ति सर्वे स शान्तिमाप्नोति न कामकामी॥

āpūryamāṇam achala-pratiṣhṭhaṁ samudram āpaḥ praviśhanti yadvat tadvat kāmā yaṁ praviśhanti sarve sa śhāntim āpnoti na kāma-kāmī

Just as the ocean remains undisturbed though waters constantly flow into it, so too the sage remains undisturbed by desires that flow into the mind. Such a person attains peace, not one who craves objects.

— Bhagavad Gita 2.70

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)