We recommend that translators begin a new paragraph here (so Revised Standard Version, Good News Bible).

When Jonathan heard the words of Apollonius, his spirit was aroused: His spirit was aroused means “he became angry” (Good News Bible). Apollonius wanted Jonathan to react to his message in this way. A possible model for this sentence is “Jonathan was furious when he received this message [or, read this letter].”

He chose ten thousand men and set out from Jerusalem, and Simon his brother met him to help him: The verb chose implies that Jonathan picked “elite troops” (Good News Bible; compare the comments on “picked” at 1Macc 4.28 and 6.35). This sentence may be rendered “He set out from Jerusalem with 10,000 of his best soldiers. While they were marching, his brother Simon joined him to help him [or, with reinforcements].”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.