The conceptual basis for this rule is the principle of equality, its importance, and the severe harm caused by deviating from it. In the case of the High Court of Justice 935/89 Ganor v. the Attorney General, IsrSC 44 (2) 485, 512 (1990), the Honorable President E. Barak held:
"In exercising his discretion, a plaintiff must act with equality and without discrimination... Proper operation of the criminal proceedings is based on the public's trust in the prosecution authorities and on the belief that they make their decisions with equality. Filing charges in a discriminatory manner undermines the public's trust in the prosecuting authorities. This is a serious blow to the democratic regime. This difficulty is threefold: first, a discriminatory use of the power of prosecution undermines the assumptions underlying the granting of discretion to the plaintiff; Second, discrimination in the filing of charges harms the public's trust in the prosecution authorities in particular and government authorities in general, and thus erodes the bonds that bind the members of society; Third, the unequal exercise of the power of prosecution harms the deterrent power of criminal law."
For the first time, the court discussed this ground and its components at length, in 1999 in the case of the High Court of Justice 6396/96 Zakin v. Mayor of Be'er Sheva, IsrSC 35 (3) 289 (1999, hereinafter: the Zakin case). Although, the argument was raised and discussed in general even before that (see, for example, the words of the Honorable Vice-President, Justice M. Cheshin inCriminal Appeal 3520/91 Turgeman v. MI, IsrSC 47 (1) 441 (1993). In the Zakin case, the prosecution of bylaws regarding signage was discussed, when it was claimed that only those who wrote criticism and protest against the mayor were prosecuted. The Honorable Justice Y. Zamir noted the essence of selective enforcement (ibid., at p. 305): "Enforcement that violates equality in the sense that it distinguishes for the purpose of enforcement between similar persons or similar situations in order to achieve an improper goal, or on the basis of extraneous consideration or on the basis of mere arbitrariness."