On the left arm of each prisoner, a number was engraved with The number became the prisoner's sole identification. Elie's tattoo read "A-7713". He observes, "I became A-7713...after that I had no other name" (Chapter 3).
The identification of the Jewish prisoners featured a serial number tattoo engraved on the person’s body. In other instances, a badge was used. The process was carried out by older prisoners using needles. After the process, the individual’s only form of identification with the German officials was the number tattooed on their body. Only prisoners who arrived at Auschwitz got the tattoo because they made it through their first selection and qualified for forced labor at the different camps. Eliezer’s number was A-7713, tattooed on his left arm, and it was the number used to refer to him by the different German officials.
“After eating, you’re to go to the dentist” (Chapter 4)
It should be noted that the series starting with the letter “A” was introduced in 1944 to cater for the increasing number of Jews from Hungary. The numbers assigned to the prisoners ended at 20,000, and then the letter preface progressed to “B”, and the count started over again.
In Chapter Three of Night, Eliezer and his family arrive at Birkenau, where the "selections" begin and families are separated. Eliezer learns from another prisoner that the Nazis have brought the Jewish people to Auschwitz in order to kill them; those who are not burned by the crematoria will be forced to perform hard labor in the prison camps. Eliezer and his father nearly escape the burning pits and are sent to the barracks; however, he is separated from his mother and sister, and we later discover that both died in the concentration camps.
Once admitted to the barracks, the Jews are stripped naked, shaved, "disinfected," and then issued a uniform. In order to identify them within the camp—and to further dehumanize them—they are tattooed with a number on their left arm. Eliezer's identification number is "A-7713," which essentially ends up becoming his "name."