Sonnet 31:
In Sonnet 31, the speaker compares his beloved's beauty to the grandeur of a summer day, acknowledging that both are subject to the relentless march of time. He laments the fact that time will inevitably diminish their physical beauty and youthful vitality. Despite this recognition, the speaker remains steadfast in his love, choosing to focus on the enduring qualities of their inner worth and the timeless nature of their love, which transcend the limitations of time.
Sonnet 39:
Sonnet 39 further delves into the speaker's reflections on the passage of time and the effects of aging on his beloved. He acknowledges the physical changes that have taken place, comparing his beloved's aging face to a book whose pages have been weathered and worn. However, the speaker finds beauty and wisdom in these wrinkles, seeing them as a testament to their shared journey and the experiences that have shaped their love. He remains undeterred by the passage of time and reiterates his unwavering love and devotion to his beloved.
Both Sonnets 31 and 39 explore the bittersweet nature of time's passage and the ephemeral beauty of youth, while emphasizing the enduring and transformative power of true love.