# of strange speech or a difficult language
"who speak a strange or difficult language"
# not to many peoples of strange speech
"I am not sending you to a mighty nation whose people speak a strange language"
# if I sent you to them, they would have listened to you
This is a situation that could have happened, but it did not. Yahweh did not send Ezekiel to people who did not understand his language. (See: [[rc://en/ta/man/translate/figs-hypo]])
# if I sent you to them
The word "them" refers to a mighty nation other than Israel.