George Gutherie on Hebrews 10:19-25 in The NIV Application Commentary on Hebrews
"One role of this passage. As to its roles, we have already noted that 10:19-25 echoes 4:14-16, forming the close of an inclusio that marks the great central section of the book. Nevertheless, 10:19-25 does more than restate 4:14-16; when compared to that text, it demonstrates a development of ideas based on the intervening discussion of Christ's superior ministry. In a sense, the author has more theological material built into his exhortation at the point; material manufactured in his carefully developed arguments of Christ's person and work."
"One role of this passage. As to its roles, we have already noted that 10:19-25 echoes 4:14-16, forming the close of an inclusio that marks the great central section of the book. Nevertheless, 10:19-25 does more than restate 4:14-16; when compared to that text, it demonstrates a development of ideas based on the intervening discussion of Christ's superior ministry. In a sense, the author has more theological material built into his exhortation at the point; material manufactured in his carefully developed arguments of Christ's person and work."