"He will not fail you nor forsake you" (31:6). Can I take that promise as mine?

In this chapter the words are spoken first to all Israel (31:6) and then to Joshua (31:8), with a task: "He will destroy these nations from before you" (31:3), and "you shall go with this people into the land" (31:7). The letter to the Hebrews gives words close to these to its own readers, in another setting: "Be free from the love of money, content with such things as you have, for he has said, ‘I will in no way leave you, neither will I in any way forsake you’" (Hebrews 13:5). And it draws the answer for them: "So that with good courage we say, ‘The Lord is my helper. I will not fear’" (Hebrews 13:6). Hebrews doesn’t say which verse it is giving; words like these also come to Joshua after Moses dies, "I will not fail you nor forsake you" (Joshua 1:5). So the promise reaches Hebrews’ readers without the Jordan or the nations: what they are given is the LORD’s "he has said", and the courage to say, "I will not fear" (Hebrews 13:5-6). How far each part of a promise given to Israel and Joshua carries over is a wider question Christians answer in more than one way; on this promise, Hebrews has already spoken.