As One does Sickness over — King Lear

As One does Sickness over 1
In convalescent Mind,
His scrutiny of Chances
By blessed Health obscured-

As One rewalks a Precipice 5
And whittles at the Twig
That held Him from Perdition
Sown sidewise in the Crag

A Custom of the Soul 9
Far after suffering
Identity to question
For evidence't has been-
(F.917/J.957)
[1–12]This poem talks about King Lear and Gloucester. They have one thing in common, their "custom of the soul" suffered them from their children, Lear's two daughters and Gloucester's illegitimate son. The hint is in the second quatrain, a description of Gloucester in the cliff of Dover. The first quatrain describes King Lear's ill decision; the third quatrain is Dickinson's comment.
[1] Sickness over:: King Lear finished the disordered division of his kingdom. His little daughter got nothing for telling the truth.
[2] convalescent:: Lear's recovering by living with his two daughters.
[3] scrutiny, Chances:: Lear's chances to be verified, if his two daughters were true to him.
[4] blessed Health obscured:: the two daughters treated him worse and worse.
[5–8] Precipice, Him, Crag:: the same happened to Gloucester who misunderstood his son Edgar. He was blind and tried to jump off from the cliff.
[9] Custom, Soul:: how Lear and Gloucester were used to think and feel.
[10] Far after suffering:: they both suffered for a long time.
[11] Identity to question, evidence:: after that, they started to question the true nature of their children, based on evidence instead of their customary feelings.