In "Economy," Thoreau makes an allusion to Matthew 9:17 that reveals his disdain for unnecessary material desires and his approval of the bare necessities of living:
All men want, not something to do with, but something to do, or rather something to be. Perhaps we should never procure a new suit, however ragged or dirty the old, until we have so conducted, so enterprised or sailed in some way, that we feel like new men in the old, and that to retain it would be like keeping new wine in old bottles.
In the original King James version, the line appears as follows: "Neither do men put new wine into old bottles: else the bottles break, and the wine runneth out, and the bottles perish." In other words, people must not put new wine in old bottles, because the bottles will break and waste the wine. In the passage from Walden, Thoreau says that men really want "something to do" or "something to be." However, material concerns often obstruct this desire. So he suggests that people should not buy new stuff; they should rather renew themselves to a point where they no longer care for new things.
The phrase "new wine in old bottles" captures the essence of his claim—buying a new suit does not make one a new man; rather, one must make oneself a new man in order to wear a new suit. Furthermore, this biblical allusion demonstrates how Thoreau adapts works of religion to his own purposes without explicitly referencing them in order to establish a quasi-religious Transcendentalist view. By grounding his newfangled ideas in old works of religious literature, he expresses his extreme dislike for materialism in a way that might appeal to a wider audience.
Thoreau alludes to Shakespeare's Richard III in the first essay, "Economy," to establish that spring has begun:
There were some slight flurries of snow during the days that I worked there; but for the most part when I came out on to the railroad, on my way home, its yellow sand heap stretched away gleaming in the hazy atmosphere, and the rails shone in the spring sun, and I heard the lark and pewee and other birds already come to commence another year with us. They were pleasant spring days, in which the winter of man’s discontent was thawing as well as the earth, and the life that had lain torpid began to stretch itself.
The original line from Richard III goes as follows: "Now is the winter of our discontent / Made glorious summer by this sun [or son] of York" (Act I Scene 1). This is a conspicuous allusion; it not only appears in many other works of literature, but it is also the first line of Shakespeare's play. Richard of Gloucester speaks it in what is technically the summer, so it has a metaphorical significance: Richard refers to his own bad mood, which he chooses to blame on his being a hunchback with unattractive features.
In Walden, Thoreau uses this line to establish that winter has ended and spring has begun. But it also refers to the end of a long season of discontent—a span of many years of modern development during which people became fixated on new comforts and technologies. In later essays, too, winter at Walden Pond represents a time of discontent, or discomfort, during which Thoreau expects to be tested physically and emotionally. This allusion to Shakespeare grounds Walden in old literature and introduces the idea of seasons as a theme in the novel, both in terms of its structure and how seasons impact the author's psyche and emotions.
In the Conclusion, Thoreau makes a biblical allusion to assert the potential of modern minds:
Some are dinning in our ears that we Americans, and moderns generally, are intellectual dwarfs compared with the ancients, or even the Elizabethan men. But what is that to the purpose? A living dog is better than a dead lion.
The phrase "a living dog is better than a dead lion" comes from Ecclesiastes 9:4. It follows the line: "There is hope, however, for anyone who is among the living." In this passage, Thoreau expresses optimism for modern thinkers. After acknowledging the greatness of the ancient poets and philosophers, he insists that modern men have just as great a capacity to effect change and produce great works. The very fact of their being alive gives him hope. By likening modern men to living dogs, Thoreau conveys that while they might not seem very grand, they still have the potential to change and evolve.
Here and in other moments in the text, Thoreau prioritizes evolution and movement over static value. This allusion reflects Thoreau's hopeful, optimistic attitude toward societal reform while supporting the work's recurring theme of renewal. He undertakes an extreme experiment in solitary simplicity, and he strives to convince the reader that anyone can take life into their own hands and experience spiritual evolution. All people are, in a sense, "living dogs," who might compare themselves unfavorably to the grand pantheons of the past, but who nevertheless contain the potential to achieve greatness in their own lives.