Handel's chorus illustrates the powerfully spiritual music performed throughout his opera "Samson" by the Israelites, contrasting with the egotistical bravura of the settings which he assigns to the doomed Philistines. The passage referring to the Creation (Genesis I.3) is taken from Samson's lament for the loss of light resulting from his blindness, in Milton's Samson Agonistes, 83-5:

O first created Beam, and thou great Word,
"Let there be Light," and light was over all;
Why am I thus bereav'd thy prime decree?

This detail from Milton's exploration of Samson's dawning self-awareness is transposed by Handel into a tremendous evocation of the biblical God's power in the Creation.