turn ... hand - not in wrath, but in grace (Zec 13:7), “upon thee,” as Isa 1:26, Isa 1:27 show; contrasted with the enemies, of whom He will avenge Himself (Isa 1:24).
purely - literally, “as alkali purifies.”
thy dross - not thy sins, but the sinful persons (Jer 6:29); “enemies” (Isa 1:24); degenerate princes (see on Isa 1:22), intermingled with the elect “remnant” of grace.
tin - Hebrew, bedil, here the alloy of lead, tin, etc., separated by smelting from the silver. The pious Bishop Bedell took his motto from this.