Śatapatha Brāhmaṇa ("of a hundred paths") 5.4.3.21

5.4.3.21

varuṇasavo vā eṣa yadrājasūyam | pṛthivyu haitasmādbibheti mahadvā ayamabhūdyo 'bhyaṣeci yadvai māyaṃ nāvadṛṇīyādityeṣa u hāsyai bibheti yadvai meyaṃ nāvadhūnvīteti tadanayaivaitanmitradheyaṃ kurute na hi mātā putraṃ hinasti na putro mātaraṃ tasmādevaṃ japati

Now this Râgasûya is Varuna's consecration; and the Earth is afraid of him, thinking, 'Something great surely has he become now that he has been consecrated: I fear lest he may rend me asunder!' And he also is afraid of her, thinking, 'I fear lest she may shake me off.' Hence he thereby enters into a friendly relation with her; for a mother does not injure her son, nor does a son injure his mother: therefore he mutters thus.