Verse
अन्नाद्भवन्ति भूतानि पर्जन्यादन्नसंभवः ।यज्ञाद्भवति पर्जन्यो यज्ञः कर्मसमुद्भवः ॥
From food creatures come into being, from rain is the birth of food, from sacrifice comes into being the rain, sacrifice is born of work; work know to be born of Brahman, Brahman is born of the Immutable; therefore is the all-pervading Brahman established in the sacrifice.
Gītā 3·14