Albert Barnes Commentary Ezekiel 3:6

"not to many peoples of a strange speech and of a hard language, whose words thou canst not understand. Surely, if I sent thee to them, they would hearken unto thee." — Ezekiel 3:6 (ASV)

To many people - To various nations using diverse languages.

Surely - The thought is that expressed by our Savior Himself (margin reference). Some render it: but I have sent you to these; they can listen etc.