Aeschylus Quoted in Robert F. Kennedy's Speech

I was reading a book Great Speeches: Words that Shaped the World by Edward Humphreys and John Boyes this afternoon. While skimming through, I found the speech that Robert F. Kennedy made on Martin Luther King's death. It's quite an inspiring speech, which talks about peace and equality. In his speech, Kennedy quoted Aeschylus.  His version:

Even in our sleep, pain which cannot forget

falls drop by drop upon the heart,

until, in our own despair,

against our will,

comes wisdom

through the awful grace of God.