וַיַּמְלֵ֨ךְ מֶֽלֶךְ־מִצְרַ֜יִם אֶת־אֶלְיָקִ֣ים אָחִ֗יו עַל־יְהוּדָה֙ וִיר֣וּשָׁלִַ֔ם וַיַּסֵּ֥ב אֶת־שְׁמ֖וֹ יְהוֹיָקִ֑ים וְאֶת־יוֹאָחָ֤ז אָחִיו֙ לָקַ֣ח נְכ֔וֹ וַיְבִיאֵ֖הוּ מִצְרָֽיְמָה׃ (פ)
Y constituyó el rey de Egipto á su hermano Eliacim por rey sobre Judá y Jerusalem, y mudóle el nombre en Joacim; y á Joachâz su hermano tomó Nechâo, y llevólo á Egipto.
Rashi
and he changed his name to Jehoiakim It is the custom of kings and princes to bestow a by-name upon their servants as they wish. An example is (Gen. 41:45): “And Pharaoh named Joseph, etc.,” and so (Num. 13:16): “and Moses called Hoshea the son of Nun, Joshua,” and so, (Dan. 1:7): “Now the chief officer gave them names, etc.” All this is to make known that he rules over him to name him as he desires.
Rashi
and he changed his name to Jehoiakim Why did he change his name to Jehoiakim? It is explained above that after Pharaoh slew Josiah, he appointed a king and fined them by imposing a tribute of enslavement upon them.