Ramayana
क्षरन्तीं च पयस्तत्र सुरभिं गामवस्थिताम् । यस्याः पयोभिनिष्यन्दात्क्षीरोदो नाम सागरः ॥ 7-23-21 ॥
There he saw stationed the cow Surabhi, pouring forth her milk, from the flowing of whose milk arose the ocean named Kshiroda, the Sea of Milk.
english translation