Shekalim 1:2-3
Shekalim 1:2
Rabbi Yehuda said that, originally, the representatives of beis din would uproot the mixed species that they found and throw them at the feet of the owners (to chastise them). When the number of violators increased, they would uproot the mixed species and throw them in the road. Ultimately, they just started declaring violators’ fields ownerless.
Shekalim 1:3
On 15 Adar, money changers would sit in the country to collect the half shekel. On 25 Adar, they would sit in the Temple. Once they moved to the Temple, they would take collateral to ensure that everybody gave the half shekel. They would take collateral from Levites, Israelites, converts, and freed slaves but not from women, children or current slaves. If a minor’s father started giving a half-shekel for his child, he must continue to do so until the child reaches the age of majority. Collateral was not taken from kohanim out of respect for the sacrificial service they performed.