give mutual help in an emergency; help each other in case (/time) of need ? 他們倆保證～，永不失信。Both of them pledged to help each other in case of need and never break their promise.
緩急相助huan ji xiang zhu
help each other in time of need or in an emergency
緩急相助huǎn jí xiānɡ zhù
緩：和緩；急：危急。無論在平時還是在危急時刻都要互相幫助。help each other in case of need, help each other in time of need, give mutual help in an emergency