Musar su Levitico 19:2

Rabbi Chiyah taught in Vayikra Rabbah 24,5 that this portion was read out during the הקהל ceremony because so many basic elements of the Torah are contained therein. Yalkut Shimoni at the beginning of פרשת ויקהל states that the teachers of aggadic material concurred that there is no other portion of the Torah which starts with a report of the Jewish people all being assembled. G–d asked Moses to arrange for many mass meetings at which the laws of Sabbath observance would be taught. Subsequent generations were meant to learn from Moses how to teach Torah in public gatherings with the objective to glorify the name of G–d among the people. This is why Rabbi Chiyah was convinced that the portion of קדושים was read on the occasion of הקהל [a public gathering of the entire nation including women and children as per Deut. 31,12 at which the people were to hear and learn to fear the Lord. Ed.] Rabbi Chiyah further supports this by the opening verse in our פרשה.

The answer to this is that Separation is certainly needed and essential. Our sages of blessed memory exhorted us on this saying (Torat Kohanim 19:2): "'you shall be holy' (Vayikra 19:2) - you shall be Perushim (men of Separation)".

Likewise, to be stringent in cases of doubt even in situations where one may be lenient. Our sages, of blessed memory, explained the statement of Yechezkel (Chulin 37b) "'behold my soul never became Tamei (spiritually unclean)' (Yechezkel 4:14) - for I never ate the flesh of an animal which a Sage was called to rule on nor did I ever eat the flesh of an animal about which one says "slaughter it, slaughter it [urgently]". Behold, all these things are certainly permitted according to the Halacha but he was stringent on himself and abstained.