左券

a sure thing / a certainty / copy of a contract held by a creditor

surname Zuo

left / the Left (politics) / east / unorthodox / queer / wrong / differing / opposite / variant of 佐[zuo3]

bond (esp. document split in two, with each party holding one half) / contract / deed (i.e. title deeds) / ticket / voucher / certificate

variant of 券[quan4]

to be assured of success (idiom)