I personally believe its about how he is going to war and is praying he comes back home to his mother. This is the poem -Mother, shed no mournful tears,
But gird me on my sword;
And give no utterance to thy fears,
But bless me with thy word.
The lines are drawn! The fight is on!
A cause is to be won!
Mother, look not so white and wan;
Give Godspeed to thy son.
Now let thine eyes my way pursue
Where'er my footsteps fare;
And when they lead beyond thy view,
Send after me a prayer.
But pray not to defend from harm,
Nor danger to dispel;
Pray, rather, that with steadfast arm
I fight the battle well.
Pray, mother of mine, that I always keep
My heart and purpose strong,
My sword unsullied and ready to leap
Unsheathed against the wrong.