Śrīmad-Bhāgavatam · Text 10.20.26
Who is speaking and story frame
धेनवो मन्दगामिन्य ऊधोभारेण भूयसा ।
ययुर्भगवताहूता द्रुतं प्रीत्या स्नुतस्तना: ॥ २६ ॥
dhenavo manda-gāminya
ūdho-bhāreṇa bhūyasā
yayur bhagavatāhūtā
drutaṁ prītyā snuta-stanāḥ
The cows had to move slowly because of their weighty milk bags, but they quickly ran to the Supreme Personality of Godhead as soon as He called them, their affection for Him causing their udders to become wet.
Read the purport on Vedabase.ioFrom Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.