Sanhedrin chapter 5, mishnah 1. The mishnah discusses questions known as chakiros. The Rishonim debate how many categories of questions exist: whether there are only two - chakiros and bedikos, or perhaps three - chakiros, derishos, and bedikos. In any event, although fundamentally these three words are synonymous, 'chakirah' as a technical term in legal jargon refers to those questions which, if the witnesses answered "I do not know" to them, their testimony is completely invalidated and is unacceptable under any circumstance.
The main purpose of the chakirah questions is to clarify the time and place in which the act in question occurred, and when and where the witnesses claim they were. This clarification is necessary, since the testimony must be capable of being refuted by hazamah: hazamah is a situation in which other witnesses claim that these witnesses were not in that place at that time. Therefore, the exact place and time must be established, and without them the testimony is not accepted at all.
The chakirah questions are derived from the expressions "and you shall inquire", "and you shall search", and "and you shall ask" that appear in three Torah portions: regarding a subverted city, idol worship, and conspiring witnesses. Through various Torah expositions they are combined together, counting seven different mentions for this type of questioning. It turns out that although the mitzvah to interrogate the witnesses to ensure they are telling the truth is from the Torah, the specific requirement to ask exactly these seven questions regarding time and place is from the Sages.
The Seven Chakiros Enumerated in the Mishnah:
The mishnah says: "Hayu bodkin osan besheva chakiros" - They would examine them with seven chakiros. The two witnesses are interrogated separately, each witness isolated from his fellow, and they begin with the older of the two. And these are the questions:
"Be'eizeh shavua" - In which seven-year cycle did the act occur. In our days there is a simpler way to count dates, but in their time they referred to the Yovel cycle: seven Shemittah cycles of seven years make forty-nine years, and the fiftieth year is the Yovel year.
"Be'eizo shanah" - In which year out of the seven years of the Shemittah cycle. This detail is well known to them, since they are careful regarding Maaser Ani and Maaser Sheni and know which year they are holding in.
"Be'eizeh chodesh" - In which month did the act occur.
"Bekamah bachodesh" - What is the date in the month, such as the seventeenth of Sivan.
"Be'eizeh yom" - Which day of the week: Thursday, Shabbos, and so on.
"Be'eizo sha'ah" - What is the hour of the day. In those days they did not wear watches; there were sundials, but not on every person's wrist and not on every street corner. The determination was made according to the position of the sun in the sky - whether it was in the first half of the day or the second, and whether the sun had risen a quarter, half, or three-quarters of the way to its peak height. In a later mishnah we will discuss the level of precision required.
"Be'eizeh makom" - Where exactly did the act occur.
To illustrate the first two questions: let us assume we are standing in the tenth year of the fifty years of the Yovel cycle. To the question "Be'eizeh shavua" - this is the second cycle, since the first cycle is the first seven years, and the second cycle is from the eighth year to the fourteenth year. To the question "Be'eizo shanah" - this is the third year of the Shemittah cycle: the eighth year is the first, the ninth is the second, and the tenth year in question is the third.
These seven questions must be asked in each and every case, and so is the halachah in the words of the poskim.
The View of Rabbi Yosi:
Rabbi Yosi disagrees, but his disagreement is much narrower than it appears. In his opinion, there is no necessity to ask all the questions, since if it is implied from the testimony itself which seven-year cycle and which year is being discussed - there is no longer a need to ask about them, and the matter becomes redundant. For example, if the witnesses came and said: "We saw Reuven bowing to an idol last Tuesday" - from this phrasing the seven-year cycle, the year, the month, and even the date are understood. In such a case, as well as one who says "I saw what happened yesterday" or "the day before yesterday", limited questions are sufficient: which day of the week, which hour of the day, and in which place. However, the halachah appears to follow the Tanna Kamma, and the Rambam indeed cites that we ask all seven questions.
Additional Questions to Clarify the Nature of the Offense:
The mishnah is not finished, and this is no longer the view of Rabbi Yosi. The Rambam, whose ruling is the halachah, groups these questions together with the chakiros, because the witnesses must also know the answer to them, and if they said "I do not know" - again the testimony is not accepted. These questions clarify exactly which crime was committed. For when one concludes the ruling that a certain person must be executed for a certain act, one must know exactly what the crime was, and without this it is impossible to put him on trial and execute him, Heaven forbid.
In a case of murder:
"Makirim atem et hamet" - did you know the victim, and was he a Jew.
"Hitreitem bo" - was the accused given a proper warning. Without dwelling on the laws of warning, in short: the transgressor must be given an official warning and told that he is forbidden to do this because it is a desecration of Shabbos, and that if he does so, Beis Din will put him to death. The reason for this is that we must know that he acted willfully and intentionally, and not because he did not know it was forbidden, or that he forgot, or that he did not understand the consequences. Not only must he receive a warning, but he must accept the warning upon himself and say, "Nevertheless" - meaning: I know, I am not concerned, and I am doing it anyway. This is how we know that he understood, heard, and acted intentionally. Furthermore, he must act immediately, within the time it takes to speak, because otherwise we suspect that he may have been distracted in the meantime.
In a case of idol worship:
"Et mi avad" - which idol, and which of the false gods did he worship.
"Bameh avad" - in what manner did he worship it: did he bow down, offer a sacrifice, or pour a wine libation. This detail is essential, because one who hugs and kisses an idol - although this is not a light matter at all, and carries a liability for lashes and the like - this is generally not formal worship, unless that is the specific manner of worship for that particular idol. Therefore, it is necessary to clarify exactly what happened before bringing him to trial.
According to the Rambam, these questions are included together with the cross-examinations, while Rashi implies that they are not. In any case, the halachah follows the Rambam. This concludes the first Mishnah.