E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Hob and Nob
together. To drink as cronies, to clink glasses, to drink tête-à-tête. In the old English houses there was a hob at each corner of the hearth for heating the beer, or holding what one wished to keep hot. This was from the verb habban (to hold). The little round table set at the elbow was called a nob; hence to hob-nob was to drink snugly and cosily in the chimney-corner, with the beer hobbed, and a little nob-table set in the snuggery. (See HOB NOB.)