It is from the first verse of 'Death the Leveller' by J Shirley...
T
HE glories of our blood and state
Are shadows, not substantial things;
There is no armour against fate;
Death lays his icy hand on kings:
Sceptre and crown Must tumble down,
And in the dust be equal made
With the poor crooked scythe and spade.
As the title suggests, all of us will one day die, no matter whether we are a king or a peasant.
69. Death the Leveller. J. Shirley. The Golden Treasury