He do me a favor ,out of blue.如何翻译?

题目

He do me a favor ,out of blue.如何翻译?

答案

他没事先和我说,就过来帮助我.(就是让作者感觉比较唐突)
arrived out of the blue.
突然拜访
criticism that came out of the blue.
突如其来的批评
Her visit was out of the blue.
她突然来访.