en_tn_lite_do_not_use/psa/109/027.md

Let them know

The word "them" refers to David's accusers and the people who say bad things about him.

this is your hand

The word "this" refers to God saving him. The phrase "your hand" is a metonym for what God has done. Alternate translation: "this is your work" or "this salvation is your doing"

have done this

"have saved me"