This remark appears in the form of a question to emphasize that the disciples have difficulty understanding what Jesus has said. Alternate translation: "no one can hear it!" or "it is too hard to understand!" (See: [[rc://en/ta/man/jit/figs-rquestion]])
The verb "hear" is a synecdoche meaning to understand and agree with. Alternate translation: "accept it" or "agree with it" (See: [[rc://en/ta/man/jit/figs-synecdoche]])