Oh! none are so absorb'd, as not to feel Sweet thoughts like music coming o'er the mind: When prayer, the purest incense of a soul, Hath risen to the throne of heaven, the heart Is mellow'd, and the shadows that becloud Our state of darken'd being, glide away;...

The speaker insists that even the most preoccupied or emotionally dulled person can be reached by sudden inward “sweet thoughts,” likened to music washing over the mind. Those thoughts are connected to prayer, figured as “incense” rising heavenward—a traditional Christian image of devotion as an offering. Prayer’s effect is not merely doctrinal but psychological: it “mellows” the heart, easing hardness and dispersing the “shadows” that cloud human existence. The passage frames prayer as a restorative act that clears spiritual and mental darkness, suggesting that moments of genuine devotion can briefly lift the burdens and obscurity of mortal life.