Have not I commanded, etc Although in Hebrew a simple affirmation is often made in the form of a question, and this phraseology is of very frequent occurrence, here, however, the question is emphatic, to give an attestation to what had previously been taught, while the Lord, by bringing his own authority distinctly forward, relieves his servant from care and hesitancy. He asks, Is it not I who have commanded thee? I too will be present with thee. Observe the emphasis: inasmuch as it is not lawful to resist his command. [1] This passage also teaches that nothing is more effectual to produce confidence than when trusting to the call and the command of God, and feeling fully assured of it in our own conscience, we follow whithersoever he is pleased to lead.

Footnotes

1 - French, "C'est bien pour certain avec grande signifiance que ceci se dit d'autant qu'il n'est pas question de resister a son commandement;" "It is certainly with great significancy that this is said, inasmuch as there is no question of resisting his command." -- Ed.

Have not I commanded thee?.... The above things, to go over Jordan with the people into the land of Canaan, and to observe the law of Moses in all things, and to be of good courage, which is again repeated; consider who it is that has given these orders and instructions, the great Jehovah, the everlasting I AM, who is faithful to his promises, and able to perform. The consideration of which would serve to animate him to the work he was called unto, to encourage his faith in God, to engage in his service cheerfully and readily:
be strong, and of a good courage; See Gill on Joshua 1:6; See Gill on Joshua 1:7.
be not afraid, nor be thou dismayed; at his enemies, numerous and powerful, nor discouraged at anything in himself, any unfitness for such service, as he might think, or at any difficulties he might fear from the people he had the government of, and was to lead on; it was enough that the divine Presence was promised him, and which is repeated:
for the Lord thy God is with thee whithersoever thou goest: or, as the Targum of Jonathan,"for thy help is the Word of the Lord thy God;''See Gill on Joshua 1:5.

In conclusion, the Lord not only repeats His exhortation to firmness, but the promise that He gave in Joshua 1:5 and Joshua 1:6. "Have I not" (nonne) is a rhetorical mode of saying, "Behold, I have," the assurance being clothed in the form of an affirmative question. On the words "be not afraid," etc., see Deuteronomy 31:6 and Deuteronomy 31:8.

I commanded thee - I whom thou art obliged to obey: I who can carry thee through every thing I put thee upon: I of whose faithfulness and almighty power thou hast had large experience?