What are the ramifications of "Vehiskadishtem"?
Rashi: It is an obligation to distance oneself from Avodah-Zarah, just as one should do with regard to Arayos. 1
Seforno: It is an obligation to keep away from Arayos. 2
Refer to 19:2:2:1 & 2. (The custom is that this Pasuk ends the fifth Aliyah, and the Arayos are discussed in the next Aliyah? Perhaps this is not because it refers to idolatry mentioned above, but because we always end and begin with something good. All the other Pesukim here discuss Kareis or Misah, except for this Pasuk and the next (which begins the sixth Aliyah - PF.)
Why does the Torah use the double Lashon "Vehiskadishtem Vih'yisem Kedoshim"?
Refer to 11:44:2:1-6.
Targum Yonasan: It means that one should also sanctify one's body before one Davens, in order that Hashem should accept one's Tefilos. 1
Seforno: The Pasuk is saying that if Yisrael keep away from Arayos, their children will be worthy of Hashem resting His Shechinah in their midst. 2
Oznayim la'Torah: Many are those who, in time of trouble or on Yom Kipur, undertake that, from that day and onwards, they will be Kadosh ve'Tahor. It doesn't take long however, for them to revert to their old habits. 3 Therefore the Torah writes "Ve'hiskadishtem vi'Heyisem Kedoshim!' Become holy and remain holy.
By relieving oneself before Davening - See Peirush Yonasan and Na'ar Yonasan.
Seforno: in accordance with the Gemara in Kidushin, 70b - 'The Shechinah only rests on families that are of pure descent in Yisrael'. See also Or ha'Chayim, who explains that, if you strive to sanctify yourselves, you will become holy like the angels, who are called "Kedoshim" (as the Pasuk states in Daniel, 8:13).
As the old saying goes 'Bad habits die hard!'
Why does the Torah insert "Ki Ani Hashem Elokeichem" here?
Seforno (citing Kidushin 70b): In keeping with Hashem's promise to Avraham 1 "Lih'yos l'cha l'Elokim u'le'Zar'acha Acharecha" - seed whose lineage comes from you.
In Lech-L'cha Bereishis, 17:7.
