Rig Veda
ऋ॒तेन॑ ऋ॒तं निय॑तमीळ॒ आ गोरा॒मा सचा॒ मधु॑मत्प॒क्वम॑ग्ने । कृ॒ष्णा स॒ती रुश॑ता धा॒सिनै॒षा जाम॑र्येण॒ पय॑सा पीपाय ॥ ऋतेन ऋतं नियतमीळ आ गोरामा सचा मधुमत्पक्वमग्ने । कृष्णा सती रुशता धासिनैषा जामर्येण पयसा पीपाय ॥
I solicit, Agni, the milk of the cow, essential for the sacrifice; yet immature, (she possesses) the sweet and ripe (fluid); black though she be, yet with her white nutritious milk she maintains mankind in existence.
english translation