put one’s hand on something—(also: lay one’s finger on something) find or locate smth.:
- I’m afraid I can’t put my hand on your letter just at the moment.
put one’s hand to something—
1. undertake a task; engage in smth.:
- After her husband died, she put her hand to the job of sorting out his papers.
2. (of a document) sign:
- Once you have put your hand to a contract, it is legally binding.