Fly, envious Time, till thou run out thy race: Call on the lazy leaden-stepping Hours, Whose speed is but the heavy plummet's pace; And glut thyself … - John Milton

The hungry sheep look up, and are not fed,
But, swoln with wind, and the rank mist they draw,
Rot inwardly, and foul contagion spread:
Besides what the grim wolf with privy paw
Daily devours apace, and nothing said;
But that two-handed engine at the door
Stands ready to smite once, and smite no more.

But to guide nations in the way of Truth
By saving Doctrine, and from error lead
To know, and knowing worship God aright,
Is yet more knightly, this attracts the Soul,
Governs the inner man, the nobler part,
That other o'er the body only reigns,
And oft by force, which to a generous mind
so reigning can be no sincere delight.

A grateful mind by owing owes not, but still pays, at once indebted and discharged; what burden then?