Robert Louis Stevenson

It is not yours, O mother, to complain
  Not, mother, yours to weep,
Though nevermore your son again
  Shall to your bosom creep,
  Though nevermore again you watch your baby sleep.

Though in the greener paths of earth,
  Mother and child, no more
We wander; and no more the birth
  Of me whom once you bore,
  Seems still the brave reward that once it seemed of yore;

Though as all passes, day and night,
  The seasons and the years,
From you, O mother, this delight,
  This also disappears --
  Some profit yet survives of all your pangs and tears.

The child, the seed, the grain of corn,
  The acorn on the hill,
Each for some separate end is born
  In season fit, and still
  Each must in strength arise to work the almighty will.

So from the hearth the children flee,
  By that almighty hand
Austerely led; so one by sea
  Goes forth, and one by land;
  Nor aught of all man's sons escapes from that command.

So from the sally each obeys
  The unseen almighty nod;
So till the ending all their ways
  Blindfolded loth have trod:
  Nor knew their task at all, but were the tools of God.

And as the fervent smith of yore
  Beast out the glowing blade,
Nor wielded in the front of war
  The weapons that he made,
  But in the tower at home still plied his ringing trade;

So like a sword the son shall roam
  On nobler missions sent;
And as the smith remained at home
  In peaceful turret pent,
  So sits the while at home the mother well content.