i got some confusing about this phrase'' pull on in this poem
Daddy's Womb
i asked my father if i could swim,
and he said that i would drown.
The Sea would imprison me – he said
if my feet had left the ground.

So i walked out to the water,
and cried out – how ’bout now!
He said, a little bit further, Son,
and then you’ll leave the ground.

i stepped on sand then stone,
from hollow ground to sturdy.
The sky was at my level as I
gazed at the birdie.

The Sea brought me a new idea,
the urge to flee to the high.

i asked my Father if i could fly,
and he said, sure, Son – go try.

i jumped as high as i could.
Still, i landed on the ground.
i saw my Father pull on a chain,
then i knew that i was bound.