The context is important, I think, so let us consider the following excerpts:
“…Blood leaked out of his mouth, but nothing else. It had happened too quickly to be absorbed. Anne knew that Nina had stabbed Clive, but she was not sure whether she had doped him as well. He was an ugly mess, and he was still alive, but Anne could find no emotion to feel for him. She had seen her sister ancient and dead on a stretcher this morning, probably because of Clive or someone like him. She did not even have any squeamishness left over. He moved feebly, trying to lift a hand to probe his wound. She felt uncomfortable, watching him die and unable to care about him. She did not know what, if anything, to do for him. So she left, and went after Nina. She did not want to think about him any more…”
Bad dreams by
Kim Newman, Simon & Schuster Ltd, London, 1990.
“…Stepping around prone shapes and viscous scarlet puddles, he peered through smoldering doorframes until the thunderous crash of a collapsing roof startled him into prudence. Only when he was satisfied nothing remained to be done did he lift a hand in signal. As he slipped noiselessly into the rainforest's camouflage of leaf and vine and root, a phalanx of phantoms melted into invisibility with him…”
Congo dawn by
Jeanette Windle, Tyndale House Publishers, IL, 2013
In either,
lift a hand doesn't seem to suggest anything like
pick up a hand, does it? If
lift a hand in signal is OK in the second one, why should it be otherwise for
lift a hand in farewell?