She handed the knife back.

她把小刀递了回去。

《柯林斯英汉双解大词典》

Put the knife back in its case.

把小刀放回鞘中去。

youdao

That done, he put the knife back in the drawer and shut it.

试过以后，又把那刀子放进抽屉，重行推上。

youdao

He leaned back against the tree to take out his knife.

VOA: special.2010.05.01

But then, most people aren't looking for a potential knife in the back.

FORBES: Magazine Article

Carlton denied the charges and lodged special defences of self defence, claiming he was attacked with the knife and fought back with it because he was "scared".

BBC: police forensic officer at the scene

This trend will create a two-tiered system of health care and could be a knife in the back of Obamacare, which relies on physician participation with insurances and its expanded patient load to survive.

FORBES: Will Your Doctor Quit? Obamacare Foretells Mass Exodus From Patient Care