I found Seamus Heaney’s poem very interesting to analyse.
The poem starts off with assonance in the first two lines, perhaps to catch our attention. It is interesting to note, however, that he does not use much rhyme nor assonance throughout the rest of it, instead giving the story a good rhythm. This, at least in my opinion, frees it from the limitations that rhyme imposes. Nevertheless, I have come to appreciate poets who are able to tell a story with rhyme, after learning that English is a very rhyme-poor language compared to say, French!
There is some repetition, notably of the theme “digging”. Perhaps Heeney doesn’t want us, or himself, to forget his roots, the farms he grew up in. Perhaps he wants to tell us a story of what motivated him, and continued to motivate him, to break free from those circumstances he described. Perhaps it was a bit of self deprecation, as despite the image of writers being cultured and educated, he appreciates that farmers like his father have and had their own hardships to face. Perhaps he was thanking his father for giving him the opportunity to have a better life. His squat pen was the tool that represented all of this.
He concludes the poem with symmetry, repeating the line “between my finger and my thumb, the squat pen rests”. After reading the poem, maybe our perception of his squat pen has changed.