"This Living Hand"

"This Living Hand" was discovered as nothing more than a few lines scribbled in the blank space on one of the last manuscripts Keat's produced. At this time, death was fast approaching the old, consumption-ridden poet and he knew it. The hand represents Keat's life work, all of his poetic endeavors, his artistic medium, and his own life, all of which will soon be "in the icy silence of the tomb". Keats, a man obsessed with his own mortality, knew that his life was coming to an end. Perhaps these few lines written undignified in the margins came from a moment of fear and a desire to reach out to future readers.

His hand, "now warm and capable" is temporally shifted to the future, where it is cold and dead. His poetry, which at the time of the poem's writing was filled with "red life" and was fresh and new, would soon be in a tomb, drained of all it's living energy. Keats tells us future readers that this hand and his poetry will "haunt thy days and chill thy dreaming nights". He tells us that his hand, his means of poetic production, will haunt us so fervently that we as readers will wish to drain our "own heart dry of blood" in order to revive it. His hand then arrives in a place that is not quite the time of writing, nor the future, with Keats saying "I hold it towards you". Whether the hand being held towards us is warm or cold is not said. Perhaps Keats wrote these few lines to represent a hope of his, a hope that his poetry would have such a drastic effect upon future readers. Perhaps Keat's wished that his own mortality could somehow be reversed in the future as a result of this effect. We will never know. Unfortunately for Keats, and for modern lovers of his poetry, we are unable to revive that once living hand.

Questions
What is the meaning of the phrase "capable of earnest grasping"?
Why would reviving Keat's hand bring a modern reader peace?