Final answer:
In Seamus Heaney's 'Digging,' the poet compares his pen to his father's spade, contrasting manual labor with the act of writing, while viewing both as tools for their respective crafts.
Step-by-step explanation:
In Seamus Heaney's poem Digging, there is a comparison made between the pen of the poet and his father's spade. The poet contrasts the tradition of manual labor exemplified by his father's and grandfather's work with his own vocation as a writer. While his ancestors dug into the soil of the Irish farmland, the poet digs into the soil of language and tradition, excavating memories and experiences to construct his poetry. Heaney's pen is thus metaphorically compared to his father's spade in the sense that both are tools for their respective work - one for farming, the other for writing.