Ver. 7. Only be thou strong and very courageous, &c.— God requires of Joshua fortitude and courage; which, indeed, ought necessarily to adorn the character of every person raised to the government of a nation; that so, being always faithful in the cause of religion, he may enforce its duties on his subjects, both by his injunctions and his example. Jehovah requires his observance of no other rule for his conduct, than that law which had been deposited with him. He forbids him in any thing to deviate from that law; and, on this condition, assures to him the most happy success.
That thou mayest prosper whithersoever thou goest— The sense given to this passage by the LXX, is very fine: That thou mayest perform wisely whatsoever thou hast to do. It is the greatest policy to be truly religious. Princes who govern by pretended reasons of state, in contempt of the commands of God, are strangers both to true wisdom and their real interest.
Joshua was to entertain far other sentiments. It was essential to the success of his ministry and arms, that his whole disposition, from the very beginning, should display his fear of God. We should observe, however, that the expression in the original, which primarily signifies to have intelligence, signifies also, frequently, to prosper; inasmuch as prudence is the path to success.