Śatapatha Brāhmaṇa ("of a hundred paths") 5.2.1.19

5.2.1.19

bṛhaspatisavo vā eṣa yadvājapeyam | pṛthivyu haitasmādbibheti mahadvā ayamabhūdyo 'bhyaṣeci yadvai māyaṃ nāvadṛṇīyādityeṣa u hāsyai bibheti yadvai meyaṃ nāvadhūnvīteti tadanayaivaitanmitradheyaṃ kurute na hi mātā putraṃ hinasti na putro mātaram

Now the Brihaspati consecration is the same as the Vâgapeya; and the earth in truth is afraid of that (Sacrificer), thinking, 'Something great surely has he become now that he has been consecrated: I fear lest he may rend me asunder!' And he himself 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 hurt her son; neither does a son hurt his mother.