Both of these statements mean the same thing. Jesus is emphasizing that the disciples should tell everyone what he tells the disciples in private. Alternate translation: "Tell people in the daylight what I tell you in the darkness, and proclaim upon the housetops what you hear softly in your ear" (See: [[rc://en/ta/man/translate/figs-parallelism]])
Here "darkness" is a metonym for "night" which is a metonym for "private." Here "daylight" is a metonym for "public." Alternate translation: "What I tell you privately at night, say in public in the day light" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Housetops where Jesus lived were flat, and people far away could hear anyone speaking with a loud voice. Here "housetops" refers to any place where all people can hear. Alternate translation: "speak loudly in a public place for all to hear" (See: [[rc://en/ta/man/translate/figs-metonymy]])