Why does it say "Ohavei Hashem"?
Malbim: Before it discussed general Hashgachah via the Ma'arachah and nature, via without Hashem conducts the world in general. They serve the Heavenly legion - "Asher Chalak Hashem Elokecha Osam l'Chol ha'Amim (Devarim 4:19). Now it turns to Yisrael and their Tzadikim, who cling to Hashem, like a son under his father's Hashgachah Pratis encompassing all his matters, amidst love.
What "Ra" will they hate?
Radak: It is every evil person.
Malbim: It is evil. Love of Hashem is love of absolute good and the source of good.
What is the significance of "Shomer Nafshos Chasidav"?
Radak: There will be no Safek about Hashem seeing Resha'im's deeds, for He saved His Chasidim from them, and took them out of their Galus.
Malbim: Yisrael are not under the Ma'arachah; Hashem saves them. Their Nefashos are a 'part' of Hashem, so He loves and clings to them like a father to his son. He saves each Nefesh with personal Hashgachah. This is unlike the nations; their Hashgachah is for the Klal (the entire nation), and based on the Ma'arachah. Individuals are not saved from evil [people] with choice.
