Gratitude of different faculties
Patience and Gratitude - Ibn Qayyim al-Jawziyyah
A man said to Abu Hazim: "What is the gratitude of the eyes?" He said "If you see good things, you speak about them, and if you see bad things, you keep quiet about it." He asked "What is the gratitude of the ears?" He said, "If you hear something good, you accept it, and if you hear something bad, you reject it." Then he asked "What is the gratitude of the hands?" He said, "Do not take that which does not belong to you and do not hold back from paying the dues of Allah (zakat)." Then he asked, "What is the gratitude of the head?" He said "To have knowledge in it." Then he asked "What is the gratitude of one's private parts?" He quoted: "Who guard their private parts, except from those joined to them in the marriage bond, or (the captives) whom their right hands possess - for (in their case) they are free from blame, but those whose desires exceed those limits are transgressors." (23:5-7)
As for those who only pay lip service to gratitude, and do not give thanks with the rest of their faculties, are concerned, they are like a man who has a garment, and all he does with it is touch it, but he does not put it on: it will never protect him from heat, cold, snow or rain.