Śatapatha Brāhmaṇa ("of a hundred paths") 1.7.1.2

1.7.1.2

tamācinatti | iṣe tvorje tveti vṛṣṭyai tadāha yadāheṣe tvetyūrje tveti yo vṛṣṭādūrgraso jāyate tasmai tadāha

That (branch) he cuts off, with the formula (Vâg. S. I, 1 a, b), 'For sap (I cut) thee! for pith thee!'--'for rain thee' he means to say, when he says 'for sap thee;' and when he says 'for pith thee' he means to say 'for that food-essence which springs from the rain.'