Our mouth is open unto you (το στομα ημων ανεωιγεν προς υμας). Second perfect active indicative of ανοιγω and intransitive, stand open. He has kept back nothing in his portrayal of the glory of the ministry as the picture of the open mouth shows.

Our heart is enlarged (η καρδια ημων πεπλατυντα). Perfect passive indicative of old verb πλατυνω, to broaden, from πλατυς, broad. In N T. only here and Matthew 23:5 (cf. phylacteries). Hence his freedom of speech for "out of the abundance of the heart the mouth speaks" (Matthew 12:34).