A.T. Robertson Commentary Luke 19:23

"then wherefore gavest thou not my money into the bank, and I at my coming should have required it with interest?" — Luke 19:23 (ASV)

Then wherefore (κα δια τ). Note this inferential use of και- in that case.

Into the bank (επ τραπεζαν). Literally,

upon a table . This old word τραπεζα, from τετραπεζα (τετρα, four, πους, foot). It means then any table , food on the table (Acts 16:34), feast or banquet (Romans 11:9), table of the money-changers (John 2:15; Matthew 21:12), or bank as here. Our word bank is from Old English bench.

With interest (συν τοκω). Not usury, but proper and legal interest. Old word from τικτω, to bring forth. In the N.T. only here and Mt 25:27.

Should have required it (αν αυτο επραξα). Conclusion of second-class condition the condition or apodosis being implied in the participle "coming" (ελθων), and the previous question. On this technical use of πρασσω (επραξα) see Lu 3:13.