Sundays too my father got up early
And put his clothes on in the blueblack cold,
Then with cracked hands that ached
From labor in the weekday weather made
Banked fires blaze. No one ever thanked him.
I'd wake and hear the cold splintering, breaking.
When the rooms were warm, he'd call,
From this, the reader can infer that the father has a job where he has to do manual labor, since his hands ache. The hard  consonantly rhyming  ‘cracked’ and ‘ached’ emphasize the intensity of the work that the father is doing. “Blueblack” and “cracked” are rhymed for emphasis to evoke cold discomfort, but also toughness and fierce love.
Those Winter Sundays