E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
When Junius Brutus (after the death of Lucretia) formed one of the deputation to Delphi to ask the Oracle which of the three would succeed Tarquin, the response was, He who should first kiss his mother. Junius instantly threw himself on the ground, exclaiming, Thus, then, I kiss thee, Mother Earth, and he was elected Consul.