Why did God withhold the gift of 'Rest' from man ?

In "The Pulley" by George Herbert, the poet envisages God setting about the act of creating human beings. As part of this process, He's mixing together in a glass all the various gifts and blessings He's going to give us. One of these blessings is rest, which we might well think is a blessing indeed. Yet just before He's about to add rest to the mix, God hesitates. Maybe it wouldn't be such a good idea to give humans the blessing of rest after all, He thinks. Because if humans had rest, then what need would they have for God? In the words of St. Augustine:

"Thou hast made us for thyself, O Lord, and our heart is restless until it finds its rest in thee."

If God bestows the gift of rest upon us, then we'll simply adore this gift, along with all the other divine gifts and blessings, instead of the God who gave them to us. And if that happens, both God and man will be greatly impoverished as a consequence:

“For if I should,” said he, “Bestow this jewel also on my creature, He would adore my gifts instead of me, And rest in Nature, not the God of Nature; So both should losers be."