"Digging" into "Digging"

The poem “Digging” by Seamus Heaney starts out with the lines “Between my finger and my thumb/The squat pen rests; snug as a gun.”(l. 1-2). The speaker is telling the reader that in that moment he is actually holding their pen writing this poem. Then he looks out his window to see his father “digging” in a garden (l. 5). The image of his father triggers a memory from “twenty years” ago (l. 7) when his father had to dig “potatoes” in order to feed his family (l. 13). With the lines “By God, the old man could handle a spade/Just like his old man.” we learn that shovels have historically been an important tool for his family (l. 15-16). The lines “The squat pen rests./I’ll dig with it” tells us thathe has replaced the shovel with a pen.