In the third stanza the speaker vows to sing, like "committed linnets," of the "sweetness, mercy, majesty, and glories" of King Charles I. It was such talk to angry Roundheads that got him in trouble. The final lines of each stanza applaud "birds that wanton in the air," "fishes that tipple in the deep," "enlargened winds, that curl the flood," and "angels alone, that soar above," of which only the last parallel the narrator's current state. FTP, this 1642 Richard Lovelace poem asserts that "stone walls do not a prison 
In the third stanza the speaker vows to sing, like "committed linnets," of the "sweetness, mercy, majesty, and glories" of King Charles I. It was such talk to angry Roundheads that got him in trouble. The final lines of each stanza applaud "birds that wanton in the air," "fishes that tipple in the deep," "enlargened winds, that curl the flood," and "angels alone, that soar above," of which only the last parallel the narrator's current state. FTP, this 1642 Richard Lovelace poem asserts that "stone walls do not a prison make, nor iron bars a cage."
In the third stanza the speaker vows to sing, like "committed linnets," of the "sweetness, mercy, majesty, and glories" of King Charles I.
To Althea, from Prison