Seemingly a proverbial expression, this phrase bears a strong resemblance to the Archangel
Raphael's injunction to Adam at the conclusion of his survey of God's newly created
universe:
Solicit not thy thoughts with matters hid;
Leave them to God above; him serve, and fear!
Of other creatures, as him pleases best,
Wherever placed, let him dispose; joy thou
In what he gives to thee, this Paradise
And thy fair Eve; Heaven is for thee too high
To know what passes there; be lowly wise:
Think only what concerns thee, and thy being;
Dream not of other worlds, what creatures there
Live, in what state, condition, or degree;
Contented that thus far hath been revealed
Not of Earth only, but of highest Heaven.
-- Paradise Lost, VIII.167-178