Gītā Dhyāna ŚlokaAnushtubh
सर्वोपनिषदो गावो दोग्धा गोपालनन्दनः । पार्थो वत्सः सुधीर्भोक्ता दुग्धं गीतामृतं महत् ॥
Upanishads are like cows that Krishna milks and intelligent Arjuna feasts on the splendid nectar of the Gita like the calf enjoying the cow's milk.
GitaUpanishadKrishna