take someone's word for it
US /teɪk ˈsʌm.wʌnz wɜrd fɔr ɪt/
UK /teɪk ˈsʌm.wʌnz wɜrd fɔr ɪt/

1.
相信某人的话, 听信某人
to believe that what someone says is true, without checking or proving it
:
•
I haven't seen the report, but I'll take your word for it that it's accurate.
我没看报告,但我相信你的话,它是准确的。
•
He said he finished all his homework, and I had to take his word for it.
他说他做完了所有作业,我只好相信他的话。