The Hand of All was a pocket universe created by All that fueled the civilisation of the Word Lords. It was a powerhouse of phrases and verbs.
The Hand was All's finest creation according to Nobody No-one, a reality made of pure language. It was an entire universe made up of pocket worlds, millions of miniature hands of All that powered the Word Lords, but it was capable of trapping a Word Lord without him being aware of it though a Time Lord could escape if he was linked telepathically. (AUDIO: A Death in the Family)