They that have power to hurt and will do none,
That do not do the thing they most do show,
Who, moving others, are themselves as stone,
Unmoved, cold, and to temptation slow,
They rightly do inherit heaven's graces
And husband nature's riches from expense;
They are the lords and owners of their faces,
Others but stewards of their excellence.
The summer's flower is to the summer sweet,
Though to itself it only live and die,
But if that flower with base infection meet,
The basest weed outbraves his dignity:
For sweetest things turn sourest by their deeds;
Lilies that fester smell far worse than weeds.
Sonnet 94 forms part of the "Fair Youth" sequence, where in sonnets 87-96 the Youth is seen as potentially fickle and unreliable. In 90-93 the Youth seems ready to abandon the poet and forget past promises; it is possible that some act or failure to act, or some statement, in the real-life circle of the Youth's admirers has convinced the poet that his beloved is one of those who moves others but is himself "as stone", giving a false impression of his intentions. Therefore there are grounds for cautious optimism, or so the poet thinks, for the Youth may in fact remain faithful despite past suspicions. Yet there remains the thought that some evil will still destroy the poet's hopes, and optimism may prove unfounded.
"They that have power to hurt and will do none": The "hurt" is presumably emotional. According to the proverb it was thought noble to use power with restraint.
"That do not do the thing they most do show": It is not clear what this "thing" is that the Youth "shows" = it might be power, or physical beauty, or the sexual activity provoked by beauty. It may also mean the Youth's abandonment of the poet, which was prepared for and almost accepted as fact in 91-93.
"Who moving others are themselves as stone": The "moving" may refer to causing emotional; upheaval, or inciting to action; being "as stone" is normally pejorative in Shakespeare.
"Unmoved, cold, and to temptation slow": This passage also seems pejorative, although Caesar describes his own character in similar terms in Julius Caesar III.1.58-62.
"They rightly do inherit Heaven's graces": Reverses the pejorative trend of the preceding lines. ("Heaven's graces"=heaven's blessings).
"And husband nature's riches from expense": "Nature's riches" may refer to the Youth's beauty; "expense" has the meaning "waste, ruin".
"They are the lords and owners of their faces": Usually taken to mean that they exercise perfect self-control, and contrasts with the next line.
"Others but stewards of their excellence.": A steward is a household manager; the line is ambiguous, as it is unclear whether these "others" are stewards of their own excellence, or of the excellence of the perfect ones who are the "lords and owners" of their faces. The reference to physical beauty, however, seems clear.
"The summer flower is to the summer sweet": Those who possess great physical beauty are like flowers which make the summer sweet.
"Though to itself it only live and die": There is an implication of virginal aloofness in the Youth's beauty, and perhaps a reproach; there is perhaps also an echo of Paul's Epistle to the Romans (Romans 14:7-8): "For none of us liveth to himself, and no man dieth to himself".
"But if that flower with base infection meet": The poet is still worried that the Youth may, after all, be corrupt and untrustworthy - this has been the theme of the previous three sonnets and continues in the next two. "Base infection" may have a double meaning, both as metaphor and as a warning of the danger of the Youth contracting a venereal disease should he yield to temptation and actually "do" that which he "shows".
"The basest weed outdoes his dignity": the lowliest (healthy) weed is better than a (diseased) flower.
"For sweetest things turn sourest by their deeds": repeats the sentiment of the preceding line, warning the Youth of the fate that will befall him should he abandon "Heaven's graces".
"Lilies that fester smell far worse than weeds": The literal truth of the foul smell of rotting lilies seems to have been widely accepted in Shakespeare's time, but there is also a dramatic and metaphorical aspect, as the fairest flowers are expected to be fair in every sense, and never to smell rotten. This line is also found in King Edward the Third, an anonymous play of 1596 which seems to have been jointly authored by both Shakespeare and Thomas Kyd.