This day will I begin to magnify thee - One cause why the miracle now to be narrated was performed is here suggested. As Moses was declared to he sent immediately from God with an extraordinary commission by the miracles which he worked, more especially that of dividing the Red Sea in two parts, so was Joshua both sent and accredited in a like manner. (Compare Joshua 1:5, and Joshua 4:14.) Other reasons are given in Joshua 3:10; Joshua 5:1.

This day will I begin to magnify thee - By making him the instrument in this miraculous passage, he did him honor and gave him high credit in the sight of the people: hence his authority was established, and obedience to him as their leader fully secured. What must have confirmed this authority was, his circumstantially foretelling how the waters should be cut off as soon as the feet of the priests had touched them, Joshua 3:13. This demonstrated that the secret of the Lord was with him.

And the Lord said unto Joshua,.... Out of the tabernacle:

this day will I begin to magnify thee in the sight of all Israel; by working the miracle afterwards related; dividing the waters, which was done on this day, and was but the beginning of wonders; for other great and marvellous things were done for him and by him, by which it appeared he was high in the favour of God, greatly esteemed and honoured by him, and so would be great and honourable in the account of the people:

that they may know that as I was with Moses, so I will be with thee; by dividing the waters of Jordan for him, as he had divided the waters of the Red sea for Moses; which, as it was a token of his powerful presence with him, this would be a like token of it with Joshua. The Targum is,"as my Word was for the help of Moses, so shall my Word be for thy help.''

Commencement of the Crossing. - First of all (in Joshua 3:7 and Joshua 3:8), the revelation made by God to Joshua, that He would begin this day to make him great, i.e., to glorify him before the Israelites, and the command to the priests who bore the ark of the covenant to stand still in the river, when they came to the water of the Jordan; then (Joshua 3:9-13) the publication of this promise and command to the people; and lastly (Joshua 3:14-17), the carrying out of the command. אחל, I will begin to make thee great. The miraculous guidance of the people through the Jordan was only the beginning of the whole series of miracles by which the Lord put His people in possession of the promised land, and glorifies Joshua in the sight of Israel in the fulfilment of his office, as He had glorified Moses before. Just as Moses was accredited in the sight of the people, as the servant of the Lord in whom they could trust, by the miraculous division of the Red Sea (Exodus 14:31), so Joshua was accredited as the leader of Israel, whom the Almighty God acknowledged as He had His servant Moses, by the similar miracle, the division of the waters of Jordan. Only the most important points in the command of God to the priests are given in v. 8. The command itself is communicated more fully afterwards in the address to the people, in v. 13. When they came with the ark to the end of the waters of Jordan-i.e., not to the opposite side, but to the nearest bank; that is to say, as soon as they reached the water in the bed of the river-they were to stand still (vid., v. 15, and Joshua 4:11), in order, as we see from what follows, to form a dam as it were against the force of the water, which was miraculously arrested in its course, and piled up in a heap. Moses divided the waters of the Red Sea with his rod; Joshua was to do the same to the Jordan with the ark of the covenant, the appointed symbol and vehicle of the presence of the Almighty God since the conclusion of the covenant. Wherever the ordinary means of grace are at hand, God attaches the operations of His grace to them; for He is a God of order, who does not act in an arbitrary manner in the selection of His means.

And the LORD said unto Joshua, This day will I begin to magnify thee in the sight of all Israel, that they may know that, as I was with Moses, so I will be with thee.

3:7 Magnify thee - That is, to gain thee authority among them, as the person whom I have set in Moses's stead, and by whom I will conduct them to the possession of the promised land.

Jos 3:7, 8. The Lord Encourages Joshua.

7, 8. the Lord said to Joshua, This day will I . magnify thee in the sight of all Israel-Joshua had already received distinguished honors (Ex 24:13; De 31:7). But a higher token of the divine favor was now to be publicly bestowed on him, and evidence given in the same unmistakable manner that his mission and authority were from God as was that of Moses (Ex 14:31).

3:7-13 The waters of Jordan shall be cut off. This must be done in such a way as never was done, but in the dividing of the Red sea. That miracle is here repeated; God has the same power to finish the salvation of his people, as to begin it; the WORD of the Lord was as truly with Joshua as with Moses. God's appearances for his people ought to encourage faith and hope. God's work is perfect, he will keep his people. Jordan's flood cannot keep out Israel, Canaan's force cannot turn them out again.