Can someone help me find a assonance in this poem?

I do not think of you lying in the wet clay
Of a Monaghan graveyard; I see
You walking down a lane among the poplars
On your way to the station, or happily
Going to second Mass on a summer Sunday -
You meet me and you say:
"Don't forget to see about the cattle -"
Among your earthiest words the angels stray.
And I think of you walking along a headland
Of green oats in June,
So full of repose, so rich with life -
And I see us meeting at the end of a town
On a fair day by accident, after
The bargains are all made and we can walk
Together through the shops and stalls and markets
Free in the oriental streets of thought.
O you are not lying in the wet clay,
For it is a harvest evening now and we
Are piling up the ricks against the moonlight
And you smile up at us - eternally.