Proverbs 25:20 As he that taketh away a garment in cold weather, and as vinegar upon nitre, so is he that singeth songs to an heavy heart.
The feeling of cold weather can be really felt by citizens who dwells in a seasonal winter country. That feeling is what is compared to someone singing to a heavy hearted person. We can look on other proverb 31; Give strong drink unto him that is ready to perish, and wine unto those that be of heavy hearts.
Here we can see that to get a person from heavy heart status or mood, is better to give them godly good word, the True Doctrine “wine” that will comfort them and making their heart merry. A word fitly spoken is like apples of gold in pictures of silver.
“But the COMFORTER, which is the Holy SPIRIT, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.”
John 14: 26 ‘Comforter’