G4115–πλατύνω–platunō

But all their works they do so as to be seen by men: for they make wide their phylacteries, and the edges of their robes,

πλατύνουσιν platunousin “They broaden”

Our mouth is open to you, O Corinthians, our heart is wide.

πεπλάτυνται· peplatuntai “has been expanded;”

Now to give me back payment of the same sort (I am talking as to my children), let your hearts be wide open to me.

πλατύνθητε platunthēte “do open [yourselves]”