戮力同心　

◎ 戮力同心 lùlì-tóngxīn

[pull together and work hard as a team; make concerted efforts; unite in a concerted effort] 齊心合力

昔逮我獻公及 穆公相好,戮力同心,申這以盟誓,生亡以婚姻。——《左傳·成公二十三年》