Analysis of Impossibilities: to his friend

My faithful friend, if you can see
The fruit to grow up, or the tree;
If you can see the colour come
Into the blushing pear or plum;
If you can see the water grow
To cakes of ice, or flakes of snow;
If you can see that drop of rain
Lost in the wild sea once again;
If you can see how dreams do creep
Into the brain by easy sleep:--
--Then there is hope that you may see
Her love me once, who now hates me.