The repeated association of instrument and weapon gives the reader a hint as to the predominant theme of the poem. As the pen is overtly named a weapon, so the spade can by implication also be understood as a weapon. Many of the images then take on a double meaning: Rooting “out tall tops” could be mowing down men, and burying “the bright edge deep” could connote a blade cutting into flesh. “Lug,” “shaft,” and “levered” are all words that could be associated with weapons, and even the beloved “cool hardness in our hands” could mean grenades, not merely potatoes. “By God, the old man could handle a spade” might be said as admiringly by one rebel of another as by farmers of one another: “Nicking and slicing neatly” could apply to blade work as well as to spade work, and “heaving sods,” in slang, could refer to bodies as well as dirt.

This very wordplay on bodies and dirt, sods and clods, also maintains the association of living and dead that the mixed images of the poem have produced. Not only did the sound of digging begin a recollection of the father’s life, but it also was a reminder of his death as well. The potato crop grows in “mould,” in decomposition, and turf is itself concentrated decomposition. All digging, then, is in among dead things, graves, “mould,” “turf.”

The mention of these two products and the hard labor necessary to obtain them establishes the context in which Heaney is writing: He comes from a family—and, on a larger scale, a culture—that has struggled for survival. That the bog on which his grandfather cut turf was “Toner’s” implies further that the fruits of their labor may not even have been their own.

These were necessary commodities—potatoes were the staple crop, and turf was the primary source of fuel—so necessary that their failure meant the end of the community. Yet, while the father’s and the grandfather’s digging was for the purpose of providing sustenance, it has resulted in their deaths. Understanding that, the play between words that mean both men and dirt also gives further impetus to the implications of violence: These laboring men are “like dirt.”

Yet, while the implication of violence is very strong, embedded in the poem is the image of Heaney’s spade-wielding grandfather drinking milk. In sixteenth century English accounts of the Irish, one cultural characteristic regarded as strange is an Irish preference of milk to meat. Such a preference is one that speaks against blood-thirstiness. By raising this image, with its unavoidable association with the “milk of human kindness,” Heaney identifies the tendency to violence that the poem displays as an imposition by others.

Thus, in the same way as the poem cuts through the constraints of English versification, it digs up “living roots.” By taking to the pen, Heaney participates in the process of reclaiming an Irish memory and identity that has been long buried and that will provide sustenance and fuel in its own way.