After a decisive battle between Egypt and Babylon, the power of Egypt was gone. As if the writer wants to say: It is logical that Jehoiakim did not receive any more help from Egypt, isn’t it?!
The prophet Jeremiah has said more than once that the Lord will punish Judah and that he will use Babylon to do so. Thus, seeking help from Egypt is both going against the will and judgment of the Lord and also denying the political-military reality that means Egypt has been dethroned as a world power by Babylon.
7 And the king of Egypt did not come again out of his land, for the king of Babylon had taken all that belonged to the king of Egypt from the Brook of Egypt to the river Euphrates.