This quite literally striking triologism is from a poem by Robert Lowell (1917-77), which I discovered in a commentary by Seamus Heaney on Lowell’s hard-hitting ‘The Quaker graveyard in Nantucket’:
When the whale’s viscera go and the roll
Of its corruption overruns this world
Beyond tree-swept Nantucket and Woods Hole
And Martha’s Vineyard, Sailor, will your sword
Whistle and fall and sink into the fat?
In the great ash-pit of Jehoshaphat
The bones cry for the blood of the white whale,
The fat flukes arch and whack about its ears,
The death-lance churns into the sanctuary, tears
The gun-blue swingle, heaving like a flail,
And hacks the coiling life out…
‘Swingle’ means both a wooden tool for beating flax and its related verb; it also refers to the swinging part of a flail.
Source: Seamus Heaney, Finders Keepers: Selected prose 1971-2001 (London: Faber and Faber, 2003), p. 207