[One] who is suspected of Sabbatical year [violations] is not suspected of [transgressing the laws of] maaser; one who is suspected of maaser [violations] is not suspected of Sabbatical year [violations]. One who is suspected of both these [violations] is suspected of [transgressing the laws of] tahorah. But in some cases, one who is suspected of tahorah [violations] is not suspected of [violating] this one or of that one. This is the rule: Whoever is suspected of something may neither judge nor testify concerning it.