Three things come not back

Remember three things come not back
The arrow sent upon its track
It will not stay, it will not swerve
Its speed, it flies to wound or slay.
The spoken word, so soon forgot
By thee; but it has perished still
And doing work for good or ill.
And the lost opportunity
That cometh back no more to thee
In vain thou weepest in vain dost yearn
Those three will nevermore return.