Sefer HaBahir

[Rabbi Berachiah responded,] “Another interpretation: ’And if he has no silver [כסף], go to him’ (Isaiah 55:1) — [go to Him,] because He has silver! As is written, ’To me is the silver and to me is the gold’ (Chaggai 2:8). What is ’Mine is the silver and Mine is the gold’? A parable, to which this is similar: to a king who has two treasure houses, one of silver and one of gold. The name of the silver was in his right and that of gold was in his left. He said, ‘This [the silver] will be available and easy to bring out.’ He makes his words gentle, and cleaves to the poor, and directs them with calm, as is written, ’Your right hand, YHVH, glorious in strength’ (Exodus 15:6). And if one is happy with his portion — good — but if not, ’Your right hand, YHVH shatters the enemy’ (Exodus 15:6)."[The students asked,] "What is ’Your right hand, YHVH shatters the enemy’?” He said to them, “This is the gold, as is written, ’Mine is the silver and Mine is the gold.’”