What is "Shemesh u'Magen"?
Sotah 10a: Shimshon resembles a name of Hashem. Just like Hashem shields over the whole world, Shimshon shielded over Yisrael in his generation.
Shocher Tov (1:4): Hashem illuminates like the sun and covers (protects) like a shield. Radak: He is a great luminary for those who dwell in the darkness of Galus, to take them from darkness to light. He is a shield to save them from the evil of the Goyim, and protect them.
Malbim: This explains "v'Habet Pnei Mashichecha" (verse 10). There are three ways that Mashi'ach can come. (a) Through great afflictions, via which [Yisrael] will repent and be redeemed. (b) Via a time of desire and grace. (c) Via virtuous deeds. "Shemesh u'Magen" corresponds to the first way. Hashem will be a sun and shield together. He will do opposite actions. The sun illuminates and burns. Also the afflictions that will bring the light of Ge'ulah, they burn and eradicate. Hashem illuminates like the sun, but shields to protect from burning - "Hinei ha'Yom Ba Bo'er ka'Tanur...; v'Zarchah Lachem Yir'ei Shmi Shemesh Tzedakah u'Marpei bi'Chnafeha" (Mal'achi 3:19-20).
What Chen and Kavod will Hashem give?
Radak: To "la'Holechim b'Samim", who return to Him with all their hearts, He will give to them grace and honor to them in front of the Goyim; they will honor them when they leave Galus.
Malbim: This corresponds to Mashi'ach coming via a time of desire and grace (refer to 84:12:1:3). People give free gifts, but honor is only based on one's deeds; Hashem will give both.
Who will not hold back good?
Radak: The Goyim - "v'Hevi'u Vanayich b'Chotzen...", "v'Hayu Melachim Omnayich", "Cheil Goyim Tochelu" (Yeshayah 49:22-23, 61:6).
Malbim: Hashem will not. This corresponds to Mashi'ach coming via virtuous deeds (refer to 84:12:1:3).
