Ibn ‘Abbās (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "This and that are equal; meaning the pinky finger and the thumb."
There are ten fingers in the two hands. If a finger is cut off, the perpetrator must pay one tenth of the blood money given for a camel. There is no difference between any of the fingers. The pinky finger, which is the smallest finger, located at the external point of the palm, and the thumb, which is a big finger that is mainly used in holing stuff, striking, and other purposes, are equal in regards to blood money. If all the fingers of the two hands are cut off or damaged, the perpetrator has to pay the complete amount of blood money. The two feet are the same as the hands. As for the fingers, although they are obviously different and each of them has a job which could not be done by the other, all of them are equal with regard to blood money. Indeed Allah is All-Knowing and All-Aware.