william shakespeare的十四行诗中怎样理解最后两句

莎士比亚-十四行诗(节选)
SONNET #1
by: William Shakespeare
FROM fairest creatures we desire increase,
That thereby beauty's rose might never die,
But as the riper should by time decease,
His tender heir might bear his memory;
But thou, contracted to thine own bright eyes,
Feed'st thy light's flame with self-substantial fuel,
Making a famine where abundance lies,
Thyself thy foe, to thy sweet self too cruel.
Thout that are now the world's fresh ornament
And only herald to the gaudy spring,
Within thine own bud buriest thy content
And, tender churl, mak'st waste in niggarding.
Pity the world, or else this glutton be,
To eat the world's due, by the grave and thee.
对天生的尤物我们要求蕃盛,
以便美的玫瑰永远不会枯死,
但开透的花朵既要及时雕零,
就应把记忆交给娇嫩的后嗣；
但你,只和你自己的明眸定情,
把自己当燃料喂养眼中的火焰,
和自己作对,待自己未免太狠,
把一片丰沃的土地变成荒田.
你现在是大地的清新的点缀,
又是锦绣阳春的唯一的前锋,
为什么把富源葬送在嫩蕊里,
温柔的鄙夫,要吝啬,反而浪用?
可怜这个世界吧,要不然,贪夫,
就吞噬世界的份,由你和坟墓.