The poem
When cats run home and light is come, And dew is cold upon the ground, And the far-off stream is dumb, And the whirring sail goes round, And the whirring sail goes round; Alone and warming his five wits, The white owl in the belfry sits.
When merry milkmaids click the latch, And rarely smells the new-mown hay, And the cock hath sung beneath the thatch Twice or thrice his roundelay, Twice or thrice his roundelay; Alone and warming his five wits, The white owl in the belfry sits.

…and light is come…. Always fascinated me that he did not use “night”, which would have also worked … but the addition of “come” signifies that light has reached its end…. As such it is spent, completed, extinguished. So the use of “..light is come..” lingers as a glimpse of that magic moment when dusk gives way to darkness. Thank you for encouraging comments on this non-commercial blog. Tim Clark [email removed]