What's he saying?
"Since brass, nor stone, nor earth, nor boundless sea, / But sad mortality o'ersways their power,"
Since nothing in the whole world can survive forever,
"How with this rage shall beauty hold a plea, / Whose action is no stronger than a flower?"
How could something as delicate as beauty survive?
"O! how shall summer's honey breath hold out, / Against the wrackful siege of battering days,"
How could summer last forever,
"When rocks impregnable are not so stout, / Nor gates of steel so strong but Time decays?"
When things as strong as rocks and steel gates are victims to Time?
"O fearful meditation! where, alack, / Shall Time's best jewel from Time's chest lie hid?"
Where can I hide the beauty of youth so that it does not die?
"Or what strong hand can hold his swift foot back? / Or who his spoil of beauty can forbid?"
How can I prevent the ravages of time?
"O! none, unless this miracle have might, / That in black ink my love may still shine bright."
Nothing will work against time except my poems, in which my beloved will be immortalized.
Why is he saying it?
Sonnet 65 continues the theme of the two sonnets preceding it, addressing the passage of time with the similar approach of how it destroys all earthly things. Sonnet 64 discusses the "lofty towers I see down-raz'd," the "brass" which is "eternal slave to mortal rage," or a victim to war, and the destruction of "the kingdom of the shore" by the "hungry ocean." Here again, "brass, nor stone, nor earth, nor boundless sea" can escape the ravages of time.
Line 3 asks, "How with this rage shall beauty hold a plea," characterizing beauty as the plaintiff in a legal dispute. Time is thus characterized as an unfair tyrant, against which delicate beauty stands no chance in court. The legal terminology is continued in the following line with the use of the word "action." The idea of time's "rage" links Sonnet 65 to the previous sonnet. In Sonnet 64, "brass" is described as an "eternal slave to mortal rage." The term "rage" in association with time is also seen in Sonnet 13, which refers to the "barren rage of death's eternal cold."
Lines 6-8 present a metaphor of the seizure of a city, which would be the final destruction of war. In line 6, "the wrackful siege of battering days," refers to ruin and destruction with the term "wrackful," while "siege" implies the taking of a city. "Battering" calls to mind a battering ram, which is a huge beam of wood swung against the gates of a city to break them down and allow the attacking army to enter. The "rocks impregnable" in line 7 refer to the city's walls, which were thought to be impenetrable, and the "gates of steel" in line 8 are the gates of the besieged city.
Lines 10-12 pose three questions, which are answered in the final couplet. In line 10, "Time's best jewel" refers to the beauty of youth, and "Time's chest" is the place where Time eventually hides all youth: a coffin. Line 11's question, "Or what strong hand can hold his swift foot back?" suggests that Time has a "swift foot," or moves quickly, unstopped by even a strong hand held up helplessly against it. Line 12 asks how it is possible to stop time from destroying youth.
Sonnet 63 uses the same idea of the physical quality of the black ink being transformed into something alive: "His beauty shall in these black lines be seen, / And they shall live, and he in them still green." The word "green" implies youth or newness, as in the greenness of springtime. In the final couplet of Sonnet 65, the poet hopes, "That in black ink my love may still shine bright." In this case, the hope that the love will "still shine bright" is a comparison to the sun, which time obscures with clouds.