Ezekiel 3:5
For thou art not sent to a people of a strange speech and of an hard language, but to the house of Israel;
Cross-reference
Ezekiel 3:6 explains that foreign speakers would listen — deepening the rebuke against Israel's stubbornness right after the commission.
Jonah 1:2 sends Jonah to foreign Nineveh — opposite of Ezekiel's mission to Israel. Both are prophetic commissions but to contrasting audiences.
Jonah 3:2-4 preaches judgment to Nineveh, a foreign city with different speech — directly opposite to Ezekiel's mission to his own people.
Acts 26:17 shows Paul sent to Gentiles — contrasting Ezekiel sent only to Israel. Both are divine commissions but to different peoples.
Isaiah 33:19 describes a people with obscure speech — similar language to Ezekiel 3:5's 'unfamiliar speech'. Both refer to foreign nations with unintelligible tongues.
Isaiah 58:1 commands to cry out to Israel's sins — same audience as Ezekiel's mission. Both are prophets sent to their own people.