Sonnet 106 is addressed to the young man without reference to any particular event. The poet surveys historical time in order to compare the youth's beauty to that depicted in art created long ago. Not surprisingly, he argues that no beauty has ever surpassed his friend's. Admiring historical figures because they remind him of the youth's character, the poet contends that what earlier artists took for beauty was merely a foreshadowing of the youth's unsurpassed appearance: "So all their praises are but prophecies / Of this our time, all you prefiguring."
In the final couplet, the poet compares historical time with the present and finds that, although he has criticized his forerunners for their lack of definitive descriptions of beauty, he, too, is unable to describe adequately the young man's beauty. In lines 11 and 12, he surmises that earlier artisans never would have been able to do artistic justice to the young man: "And, for they looked but with divining eyes, / They had not still enough your worth to sing." However, he admits in the sonnet's last two lines that he doesn't have the necessary skills either: "For we, which now behold these present days, / Had eyes to wonder, but lack tongues to praise." Note the parallel imagery in the sonnet's last four lines, in which the past and the present are contrasted: "Eyes" are capable of viewing the youth's beauty, but previous artisans didn't have the skill "to sing" about the young man, and neither has the poet the skill "to praise" him adequately.