Bhagavad Gita · 6.42

अथवा योगिनामेव कुले भवति धीमताम्।एतद्धि दुर्लभतरं लोके जन्म यदीदृशम्॥

athavā yoginām eva kule bhavati dhīmatām etad dhi durlabha-taraṁ loke janma yad īdṛśham

Or, the unsuccessful yogi may be born into a family of wise yogis. Such a birth is extremely rare in this world.

— Bhagavad Gita 6.42

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