One Brow said: "I remember that from Ecclesiates 9:5,10, but not from Job."

Yeah, I mixed up a bit. I remembered Ecclesiates as well as Job:

Job 7:9 As the cloud is consumed and vanisheth away: so he that goeth down to the grave shall come up no more.

So, close enough. I don't think there's any way to spin that, or Ecclesiastes. All the arguments I've seen for a Hebrew belief in an afterlife do some serious twisting of verses to even remotely allow it, and ignore these ones altogether.
At the very least, you'd think a promise of heaven after death would go into the covenant, but not a word there, either.