Act for do, A.V. Received; i.e. as the word ὑποδέχομαι always means "received as a guest" (Luke 10:38; Luke 19:6; James 2:25, etc.). Hence the substantive ὑποδοχή, an entertainment or reception. The insinuation is that, by harboring these seditious men, Jason had made himself a partner in their sedition.
That there is another king, etc. (comp. John 19:12, John 19:15).