See on Act 3:12, and compare Phi 3:5, and the phrase Israel of God, Gal 6:16, and an Israelite indeed, Joh 1:48.
Seed of Abraham
Compare Mat 3:9; Joh 8:33; Rom 9:7; Rom 11:1; Gal 3:16; Heb 2:16. The three names are arranged climactically, Hebrews pointing to the nationality; Israelites to the special relation to God's covenant; seed of Abraham to the messianic privilege. Compare with the whole, Phi 3:4, Phi 3:5.