The hadd punishment for theft
Question

                the criminal punishment in muslim countrys seem to be different from the sunnah, like chopping a theifs fingers off and leaving his thumb if he stole for the first time(in iran this happens).is this sunnah?
Praise be to Allah.Theft 
          is haraam according to the Qur’aan, Sunnah and scholarly consensus (ijmaa’). 
          Allaah has condemned this action and decreed an appropriate punishment 
          for it. The hadd punishment for a thief is to cut off his hand. Allaah 
          says (interpretation of the meaning): 
“And 
          (as for) the male thief and the female thief, cut off (from the wrist 
          joint) their (right) hands as a recompense for that which they committed, 
          a punishment by way of example from Allaah. And Allaah is All Powerful, 
          All Wise” [al-Maa’idah 
          5:38]
The 
          Prophet  (peace and blessings of 
          Allaah be upon him) said: “The hand should be cut off for (the theft 
          of) a quarter of a dinar or more.” (Narrated by al-Bukhaari, al-Hudood, 
          6291)  
The 
          Prophet  (peace and blessings of 
          Allaah be upon him) cursed the thief because he is a corrupt element 
          in society, and if he is left unpunished, his corruption will spread 
          and infect the body of the ummah. He  
          (peace and blessings of Allaah be upon him) said, “May Allaah curse 
          the thief who steals an egg and has his hand cut off, or steals a rope 
          and has his hand cut off.” (al-Bukhaari, al-Hudood, 6285).  
          
What 
          indicates that this ruling is definitive is that fact that a Makhzoomi 
          noblewoman stole at the time of the Prophet  
          (peace and blessings of Allaah be upon him), and Usaamah ibn Zayd wanted 
          to intercede for her. The Prophet  
          (peace and blessings of Allaah be upon him) became angry and said, “Do 
          you intercede concerning one of the hadd punishments set by Allaah? 
          Those who came before you were destroyed because if a rich man among 
          them stole, they would let him off, but if a lowly person stole, they 
          would carry out the punishment on him. By Allaah, if Faatimah bint Muhammad 
          were to steal, I would cut off her hand.” (al-Bukhaari, Ahaadeeth 
          al-Anbiyaa’, 3216)  
This 
          is the ruling of Allaah concerning theft, that the hand should be cut 
          off from the wrist joint.  
Al-Nawawi 
          said in his commentary on Saheeh Muslim: Al-Shaafa'i, Abu Haneefah, 
          Maalik and the majority (of scholars) said: The hand should be cut off 
          from the wrist, where the hand meets the forearm. Al-Qurtubi said: all 
          the scholars said: The hand should be cut off from the wrist, not as 
          some of the innovators do when they cut off the fingers and leave the 
          thumb.  
Because 
          cutting off the hand is a serious matter, cutting off the hand of the 
          thief should not be done for just any case of theft. A combination of 
          conditions must be fulfilled before the hand of a thief is cut off. 
          These conditions are as follows:  
The 
          thing should have been taken by stealth; if it was not taken by stealth, 
          then (the hand) should not be cut off, such as when property has been 
          seized by force in front of other people, because in this case the owner 
          of the property could have asked for help to stop the thief.  
1-The stolen property should be something of worth, because 
          that which is of no worth has no sanctity, such as musical instruments, 
          wine and pigs. 
2-The value of the stolen property should be above a certain 
          limit, which is three Islamic dirhams or a quarter of an Islamic dinar, 
          or their equivalent in other currencies. 
3-The stolen property should have been taken from a place 
          where it had been put away, i.e., a place where people usually put their 
          property, such as a cupboard, for example. 
4-The theft itself has to be proven, either by the testimony 
          of two qualified witnesses or by the confession of the thief twice. 
          
5-The person from whom the property was stolen has to ask 
          for it back; if he does not, then (the thief’s) hand does not have to 
          be cut off.
If 
          these conditions are fulfilled, then the hand must be cut off. If this 
          ruling was applied in the societies which are content with man-made 
          laws and which have cast aside the sharee’ah of Allaah and replaced 
          it with human laws, this would be the most beneficial treatment for 
          this phenomenon. But the matter is as Allaah says (interpretation of 
          the meaning):
“Do 
          they then seek the judgement of (the days of) Ignorance? And who is 
          better in judgement than Allaah for a people who have firm Faith” [al-Maa’idah 
          5:50]