Someone extends their hand to you, sometimes a loved one, sometimes a stranger, and you begin to read. The words come without you having learned.
The emotional tone
An impression of calm authority, almost familiar. You don't doubt what you're saying, even if on waking you don't remember.
Symbolic meaning
Reading another's hand in a dream is symbolically occupying the witness's place. Traditions see it as a sign of intuition seeking to deploy: you perceive on the other what you don't yet dare name on yourself.
The palmistry link
Traditional palmistry considers that the ability to read always comes from oneself. The dream is a training ground, it lets you formulate safely what's asking to come out in waking life.
What this dream signals in your life
This dream arrives for people whose circle starts confiding more. They feel asked to listen, and the dream prepares them.
Reading a hand in a dream is learning to read. Yours, first.