Few requests for help are as roundabout as this one. Burns wants a letter passed on to Captain Grose, but he does not say so until the sixth of eight couplets. Before that he asks, with mock anxiety, where on earth the man has got to. Is he among friends or foes? In heaven? Drowned? Eaten? The poem runs on that gap between a plain errand and the absurd lengths the speaker goes to in delaying it.
The questions escalate in a way that is hard not to enjoy. The first is mild, since a missing traveller might be among friends or foes. Then the speaker jumps to the afterlife and asks whether Grose has gone "to Abra'm's bosom" or is "haudin Sarah by the wame". The biblical image of heaven is made cheekily physical by that last word, which means belly. Next comes plain geography, "south or … north", or "drowned in the river Forth". The sharpest joke is the fourth couplet, where Highlanders may have slain him and "eaten [him] like a wether haggis". The speaker invents a Scotland of cannibal clansmen and treats the Captain as a dish. The jokes about the *wame* and the haggis hint, as an inference from the text, at a well-padded figure. Each guess is more outlandish than the last, so by the fifth stanza the speaker has run through earth, heaven and the stomachs of the Highlands.
The refrains do much of the comic work. Every first line ends with "Igo, and ago" and every second with "Iram, coram, dago". These are nonsense syllables of the kind folk songs often carry, and the poem has the bounce of a song meant to be sung along to. Because each refrain follows a question, it sounds like an answer, but a meaningless one, as if the universe replied to "Is he slain?" with a shrug and a jingle. The syllables also keep the tone light. Even the haggis line cannot turn grim with "Iram, coram, dago" tagged on the end.
The verse itself is quick and simple. The lines before each refrain are short, about seven or eight syllables with four beats, and they pair up in rhymes: Grose and foes, north and Forth, letter and debtor, store and bore. Two of the rhymes are looser and so feel more playful: "bodies" with "haggis", and "near him" with "steer him". The Scots words, such as *ken*, *gane*, *haudin*, *daur na*, give the voice a chatty, spoken ease, as though the speaker were joking across a table.
The fifth couplet is where the mood shifts. "Where'er he be, the Lord be near him!" sounds like a sincere blessing, and then the next line tips it over: "As for the deil, he daur na steer him." The devil himself will not meddle with the Captain. It is a compliment disguised as a jibe, and it plants the devil that returns in the last stanza.
From there the poem turns to its real business: "please transmit th' enclosed letter … Which will oblige your humble debtor." The final two couplets then offer the favour-doer a reward, "So may ye hae auld stanes in store, / The very stanes that Adam bore." Judging by these stanzas, Grose's world is that of old relics, and the speaker mocks it by inflating it to the ridiculous. The ideal collector's prize would be stones from Adam's time and "the coins o' Satan's coronation". The devil who would not touch the Captain now has his coronation coins turned into souvenirs. The joke closes the circle neatly.
The poem is not a grand statement, and it is more interesting for that. Its central idea is affectionate teasing. The speaker treats a friend's absence, and perhaps his hobby too, as occasion for outrageous invention, while the useful message sits in the middle of the nonsense. Its significance lies in how much craft goes into something so light. The escalating questions, the sly pivot of the devil line, the refrains that answer nothing and the closing blessing built from the poem's own jokes all show that a favour can be asked as entertainingly as a poem can be written.