Original source?

[lifebiat4]

What is the original source of: How sweet to sleep where all is peace; where sorrows cannot reach the breast; where all life's idle throbbings cease; and pain is lulled to rest.

[Wraith]

Don't know the answer to this one. I know it has been used as an epitaph since at least 1890. I've been through the Oxford library of English poetry and found no occurrences of it, presuming of course that "How sweet to sleep where all is peace" is the first line of a poem. It could of course be a small part of a much larger poem.