One verse

Srimad Bhagavatam 3.26.59

3.26.59

नाड्योऽस्य निरभिद्यन्त ताभ्यो लोहितमाभृतम् । नद्यस्तत: समभवन्नुदरं निरभिद्यत ॥ ५९ ॥

nadyo ’sya nirabhidyanta tabhyo lohitam abhrtam nadyas tatah samabhavann udaram nirabhidyata

nadyah
the veins
asya
of the universal form
nirabhidyanta
became manifested
tabhyah
from them
lohitam
blood
abhrtam
was produced
nadyah
the rivers
tatah
from that
samabhavan
appeared
udaram
the stomach
nirabhidyata
became manifested.

The veins of the universal body became manifested and thereafter the red corpuscles, or blood. In their wake came the rivers (the deities presiding over the veins), and then appeared an abdomen.