A person finds joy in giving an apt reply— and how good is a timely word!
NMVA man has joy by the answer of his mouth: and a word [spoken] in due season, how good [is it]!
OJBAn ish hath simchah in the apt reply of his peh (mouth), and a timely davar, mah tov (how good!)
T4TPeople rejoice when they are able to reply well to what others have asked them; truly, it is very delightful to be able to say the right thing at the right time.