What does the Torah mean when it writes "Ki Hashem Elokecha Mis'halech be'Kerev Machanecha"?
Rashbam: It means that when they went to war, they took the Aron with them. 1
Targum Onkelos and Targum Yonasan: It refers to the Shechinah, that would accompany them into battle.
What does the Torah mean when it writes "Vehayah Machanecha Kadosh"?
Seforno: It means devoid of Tum'ah and things that are repulsive or a P'sul in one's offspring. 1
Seforno: As the Gemara says in Kidushin, 90b 'The Shechinah only rests among the pore families in Yisrael - which is why they said that 'Whoever was included in the list of officers of the kings of the House of David was, without doubt, of pure pedigree.
What does "Ervas Davar" refer to?
Ramban: It refers to Giluy Arayos. 1
Seforno: It refers to someone who is Pasul - whose genealogy is tainted. 2
What are the implications of the words "ve'Shav me'Acharecha"?
Seforno: It implies that 'when you turn the backs of your necks to him regarding one of the above, He will forsake you'.