Green’s Dictionary of Slang

solomon n.1

also salaman, salamon, salmon, salomon
[the biblical king, Solomon, or ? Fr. serment, an oath. Rowlands, Martin-Mark-all (1610), notes that while solomon/salomon duly means Mass, ‘Many men I have heard take this word Solomon to be the chief commander among the beggars. But to put them out of doubt, this is not he. Marry, there was one Solomon in King Henry the Eighth’s time that was a jolly fellow among them, who kept his court [...] at Foxhall (Vauxhall) [...] who was successor to Cock Lorel’]

1. [mid-16C] (UK Und.) an altar.

2. [mid-16C–mid-19C] (UK Und.) the Mass; usu. in the canting or beggars’ oath by the solomon! by the Mass!