The Torah tells us that when someone transgresses one of the Mitzvot he must bring a specific sacrifice to atone for his wrongdoing. We find, however, a different language is used for different individuals. When speaking about an ordinary person the Torah says: נֶפֶשׁ כִּי תֶחֱטָא, “…when a person will sin…” (Lev. 4,2) When speaking about a ruler who transgresses the Torah states: אֲשֶׁר נָשִׂיא יֶחֱטָא, “When a ruler sins…” (Lev. 4,22)
The English translation uses the same word “when” in both cases. The wording of the Torah though uses a different word for these two cases. For an average person the word כִּי is used. For the ruler, the word אֲשֶׁר is used. These words have different connotations. The word כִּי can be translated as “if” or “in case”. The word אֲשֶׁר is translated as “who” or “that”.
The implication in the change of the wording indicates that an ordinary person may or may not transgress. Hence the Torah says “if” or “in case” a person sins. He may or may not. When referring to a ruler the Torah states “who” or “that” sins. This implies that he will sin.
The presumption is that a ruler will most likely sin. This is in line with the common saying that power corrupts. A ruler who is given power and honor is in jeopardy of acquiring conceit and haughtiness and may take a path that will lead him to indiscretion. An honest leader will try to be careful and avoid this pitfall.