In tablet 11 of the epic of Gilgamesh, after Utnapishtim's ark lodges on a rock, he releases a dove, a swallow, and a raven, in that order. The first two birds return when they fail to find a resting place. He releases the raven, witch does not return, after which Utnapishtim opens the ark.
The NASB translation of Genesis 8:7, which of the commonly available English translations appears to me to be closest to the original in this case reads:
"And he sent out a raven, and it flew here and there until the water was dried up from the earth."
I think that the translation should "And he sent the raven, which did go out but returned to wait until the waters dried." The reasoning is that the original uses the the "heh ha'yidiah", the definite article "the" before "raven" (not "a raven", but "the raven", or possibly "the Raven" meaning the raven as a representative of it's species), and a double form of the verb to go out, "vayetse yatsu", meaning that it indeed did go out but implying a reluctance to go out. I read the clause break after "did go out" so that "v'shuv" ("then returned") applies to the "until the waters dried". The NASB reads reads the clause break after "v'shuv" so they translate "flew [went out] here and there". The NASB and similar readings are problematic in that they make it look as if the raven went out but did not come back, leaving us to ask why Noah didn't see this as a sign to open the ark.
In any event, the raven's mission is clearly a failure. The entire episode is dismissed in one verse of eleven Hebrew words.
Following the raven's mission, Noah sends the dove. The dove goes out and returns "to him", to Noah, whereas the raven just returns, but not "to him". Noah sends the dove on a second mission. Again, she returns "to him", this time with an olive twig. She is clearly a willing participant in these missions. Noah sends the dove a third time, and she does not return - she has a mission of her own now. The dove's missions take up five verses with a total of seventy-five Hebrew words.
What does the raven symbolize in the Biblical story?
It is clear that Genesis has reversed the story of birds in the flood episodes with respect to the Gilgamesh text. What is Genesis trying to tell us by this reversal?
Given that we know that in Israelite culture the raven is an "unclean" bird and the dove is a "pure" bird, what is the meaning of the failure of the raven's mission?
Finally, what was Noah thinking when he sent a raven on this mission?