What does 1 Chronicles 19:2 mean?

David thought, 'I should show kindness to Hanun, Nahash's son, because his father was good to me.' So David sent messengers to comfort Hanun about his father's death. But when David's men arrived in Ammonite territory to offer condolences, 1 Chronicles 19:2 - Modern Text Bible

(David wants to honor Nahash's memory by being kind to his son Hanun, so he sends people to express sympathy. This is a diplomatic gesture, but it sets off a misunderstanding.)