After all, we will not have long to persevere. The Lord"s return is near ( Revelation 22:20). In the meantime we need to keep walking by faith. If we abandon that purpose, we will not please God. [source][source][source]
"This observation [1] is a figure of speech called litotes in which a positive idea is expressed by negating the opposite. As the larger context makes plain, he means, "God will be severely angered" (see Hebrews 10:27)." [2][source]
The allusions in these verses are to Isaiah 26:21 and Habakkuk 2:3-4 in the Septuagint. The writer took all his Old Testament quotations from this version except the one in Hebrews 10:30, which he took from the Hebrew Bible. "My righteous one" is a believer. "Shrinking back" refers to apostasy. [3][source]
"Paul is concerned with the way a man comes to be accepted by God; the author [4] is concerned with the importance of holding fast to one"s faith in the face of temptations to abandon it." [5][source]