To understand the ending of this poem, we should keep in mind that the speaker says he is going to dig with his pen and return to the beginning. In between these first and last stanzas, the pen is never mentioned. Instead, the speaker focuses on his father and grandfather’s digging with a spade, representing them through strong verbs which suggest repeated movements, like ‘straining’, ‘stooping’ and of course, ‘digging’. By comparing his father to his grandfather, Heaney’s speaker is leading the reader into wondering how the speaker himself compares to them. What does he do if these men were so strong and able with a spade?
In this last stanza, we are given an answer: his pen is the tool by which he defines himself. Re-reading the poem, it may be worth thinking about how the pen takes part in its own kind of ‘digging’ in Heaney’s construction of the poem. Consider the significance of repetition and what it means to represent the ‘old men’ who dig in poetic form.