The Lord of peace himself (autos ho kurios tēs eirēnēs). See note on 1Th 5:23 for the God of peace himself.
Give you peace (doiē humin tēn eirēnēn). Second aorist active optative (Koiné[28928]š) of didōmi, not dōēi (subjunctive). So also Rom 15:5; 2Ti 1:16, 2Ti 1:18. The Lord Jesus whose characteristic is peace, can alone give real peace to the heart and to the world. (Joh 14:27).