The Lord’s spirit spoke through me; his word was on my tongue. – 2 Sam 23:2 NET
We read that “no prophecy of the Scripture is of any private interpretation;” that is to say, it is the public property of the whole family of Jehovah; and “holy men of God spoke as they were moved by the Holy Spirit;” the Holy Spirit so influencing and working upon their minds as to make them bring forth out of their hearts that which should be suitable to the whole family of God. For instance, we read in Psalm 51, David’s confession of sin; but David’s confession of sin applies to every soul that is condemned on account of sin. When Job, also, poured out his piteous complaints, he was speaking; though he might not know it, for the children of God to the remotest time.
So when the Lord said to Joshua, “I will never leave you, nor forsake you,” it was a promise specially given to Joshua; it seemed to be confined to that individual; it appeared to be of private interpretation, as though Joshua, and Joshua alone, was entitled to that promise. But we find the apostle Paul bringing forward this promise as the general property of the whole Church of God—“Let your life be without covetousness; and be content with such things as you have—for he has said, I will never leave you, nor forsake you” (Heb. 13:5). “He has said?” to whom? To Joshua; but in saying it to Joshua, he said it to the Church of God; in giving Joshua the promise, he gave that promise to every soul that needed with Joshua his help, that feared with Joshua to be forsaken, that wanted with Joshua his sustaining hand; and therefore this private promise to Joshua was not of private interpretation, but, when applied by the blessed Spirit, suits every living soul that is placed in similar circumstances with the individual to whom that promise was addressed.