Bhagavad Gita 3.14

अन्नद्भवन्ति भूतानि पर्जन्यादन्नसम्भव: |
यज्ञाद्भवति पर्जन्यो यज्ञ: कर्मसमुद्भव:

Translation

All living beings subsist on food, and food is produced by rains. Rains come from the performance of sacrifice, and sacrifice is produced by the performance of prescribed duties.