Having just encouraged his readers with a reminder of God"s help for the faithful ( Hebrews 1:14), the writer next urged his readers to be faithful. He did so to warn them of the possibility of retrogressing spiritually and consequently losing part of their inheritance. Jacob"s sons Reuben, Simeon, and Levi had done this. [source][source][source]
"The second step in the argument for Jesus" superiority shows him to be infinitely great because of the nature of the salvation he won.... The author precedes the development of this thought with a brief section in which he exhorts his readers to attend to what has been said, a feature we shall notice elsewhere (e.g, Hebrews 3:7-11; Hebrews 5:11-14)." [1][source]
"The author uses doctrine as a basis for exhorting believers." [1][source]
"The number of unusual words and idioms and the avoidance of the vocabulary of the LXX suggest that in this paragraph it was the writer"s intention to confront the thought and life of his readers in a more arresting way than reliance upon familiar words and phrases would foster." [3][source]