What are the connotations of the word "ha'Mechtzah"?
Rashi (in Vay'chi Bereishis, 49:23): It means the divided section. 1
See Rashi, Bereishis, 49:23.
Having issued instructions to halve the slaves and the animals, and how much to give Elazar and the Levi'im from each half, why does the Torah need to specify the amount of the half and the total of the percentage given to Elazar and to the Levi'im?
Ramban and Moshav Zekenim: To teach us the tremendous miracle that occurred - that from the time that the soldiers captured the spoil until they counted the vast amounts involved, divided it into two and separated the required amounts for Elazar and the people, not a single slave or animal died.