Laid down their own necks (ton heautōn trachelon hupethēkan). First aorist active of hupotithēmi, old verb to place under (the axe of the executioner), only here in N.T. in this sense, though in 1Ti 4:16 to suggest. If literal or figurative, the incident may be connected with the uproar created by Demetrius in Ephesus. Certainly Paul felt deep obligation toward them (see note on Act 20:34).
Not only I (ouk egō monos). Rather, “not I alone” (adjective monos). The Gentile churches also (great mission workers).