Charles Ellicott Commentary 2 Kings 18:26

"Then said Eliakim the son of Hilkiah, and Shebnah, and Joah, unto Rabshakeh, Speak, I pray thee, to thy servants in the Syrian language; for we understand it: and speak not with us in the Jews` language, in the ears of the people that are on the wall." — 2 Kings 18:26 (ASV)

Speak, I pray thee ... in the Syrian language. — Hezekiah’s ministers naturally feared the effect of Rab-shakeh’s arguments and assertions on the garrison of the city. The people, many of whom had always been accustomed to worshiping at the high places, might well doubt whether there was not some truth in the allegation that Jehovah was incensed at their removal.

In the Syrian language. — In Aramaic; which was at that time the language of diplomacy and commerce in the countries of Western Asia, as is proven by the bilingual contract tablets (in Aramaic and Assyrian) discovered at Nineveh.

In the Jews’ language. — In Jewish; an expression found only in Nehemiah 13:24 besides the present narrative. The word “Jew” (Yehûdî), from which it is derived, itself occurs only in the later biblical books; but contemporary Assyrian usage (mât Ya-u-di or Ya-u-du, “Judah; ” Ya-u-da-a-a, “the Jews”) favors the supposition that the people of the Southern Kingdom were even then called Yehûdim, and their language “Jewish” (Yehûdîth). The spoken dialect probably differed considerably from other varieties of Hebrew, though not enough to make it unintelligible to other Hebrew-speaking peoples, such as the northern Israelites and the Moabites and Edomites.