Some worries arrive with no label, and the speaker of "Purchase" gets one down to a single object: "a new coin, good in the stamp / and bad in the money." The poem is five lines long, and each of them is doing something. Its central idea is that a private trouble behaves like a coin that can't be spent. It looks like something, it has weight, it stays with you, and it can't be passed along or exchanged for anything.
The coin is a precise image. A stamp is the mark of authority, the design pressed into the metal to say what the coin is. "Money" is what it is actually worth. The poem says the two have come apart: the coin looks right but fails in use. The poem never explains the trouble, and that is what makes the image work. All we learn is its quality, something that seems legitimate and then won't function. The word "new" adds to this. The trouble is fresh and still bright, not yet worn smooth by handling.
The title keeps working after the poem ends. "Purchase" suggests buying, and the speaker is holding a coin that can't buy anything. But the word also means a grip, as in getting purchase on a rock face. The speaker has a hold on the trouble, and perhaps the trouble has one on the speaker, but neither gets any leverage. I'm reading this double sense into the title. The poem never states it, but the word is chosen so precisely that it's hard to ignore.
The setting is ordinary, and that makes the poem more convincing. "I carry a private trouble on a walk" uses a verb for bags and pockets, and "private" explains why the coin can't circulate. Money exists to be shared and exchanged, and a private trouble can't be handed over. A walk is supposed to loosen a worry, but here the worry comes along as a companion. The poem never says the walk fails to help, though the cold dinner suggests it.
The sound of the lines supports this. The first line is long and loose, almost conversational, at about eleven syllables. Then the poem tightens: seven syllables, then six, then seven, then three. The lines shrink toward the end, and the poem seems to close in on itself. There is no rhyme, which suits a poem about something that won't make a neat exchange. Even so, the sound is carefully organised. The hard "c" in "carry," "coin," and "cold" ties the opening, middle, and end together. The final phrase, "hard and cold," carries a heavy "d" echo. Its hardness is partly in the sound of the words.
The ending is the most interesting moment. "I have my dinner with it— / hard and cold." The dash opens a gap, and the grammar doesn't say what the phrase describes. It could be the dinner, left to go cold. It could be the coin, since metal is hard and cold. It could be the trouble, or the mood of the evening. The poem refuses to choose, so one description covers everything on the table. "With it" matters too. The speaker has dinner with the trouble as with a guest, which makes a worry into company, and unwelcome company at that. The domestic detail makes the poem more painful, because a meal is usually where we share things and here nothing is shared.
The poem is significant for how much it does with so little. It takes an abstract experience, a worry that can't be told or settled, and gives it a shape you could hold in your palm. It does this without explaining or consoling. The speaker never says what the trouble is, or whether it will pass, or how it feels. We only get the coin, the walk, and the cold dinner, and from those a reader can reconstruct the feeling. Anyone who has carried a worry they couldn't pass on will recognise it, and the poem asks nothing more of us than that.