water rests not on barren hill summits

From the yesterday’s Valley of Vision devotional prayer (a collection of Puritan prayers):

Help me to see myself in thy sight,
   then pride must wither, decay, die, perish.
Humble my heart before thee,
   and replenish it with thy choicest gifts.
As water rests not on barren hill summits,
   but flows down to fertilize lowest vales,
So make me the lowest of the lowly,
   that my spiritual riches may exceedingly abound.
When I leave duties undone,
   may condemning thought strip me of pride,
   deepen in me devotion to thy service,
   and quicken me to more watchful care.