“Heaven’s graces” refers to both one’s beauty and class here. This metaphor suggests that these two elements of social power come from God, which in turn elevates both beauty standards and the social hierarchy.
The words “unmoved” and “cold” carry a nuanced meaning. While these words take on a negative connotation, the speaker actually uses them to depict an ideal model of behaviour. To the speaker, “they that have power” ought to practice restraint and self-control. In his view, beautiful people should not use their beauty to take advantage of others. Rather, they should be “unmoved, cold” in the face of temptation.
The repetitive use of “do” in the first two lines is intentionally contradictory. The word brings up connotations of action, and yet the underlying point of the lines is to encourage inaction. Thus, the repetition of “do” mimics the “temptation” in line 4.
