And when the morning was come, David wrote a letter to Joab: and sent it by the hand of Urias,

And it came to pass in the morning, that David wrote a letter to Joab, and sent it by Urijah.

And it cometh to pass in the morning, that David writeth a letter unto Joab, and sendeth by the hand of Uriah;

Now in the morning, David gave Uriah a letter to take to Joab.

Therefore, when morning arrived, David wrote a letter to Joab. And he sent it by the hand of Uriah,

David wrote a letter - This was the sum of treachery and villany. He made this most noble man the carrier of letters which prescribed the mode in which he was to be murdered. This case some have likened to that of Bellerophon, son of Glaucus, king of Ephyra, who being in the court of Proetus, king of the Argives, his queen Antia, or as others Sthenoboea, fell violently in love with him; but he, refusing to gratify her criminal passions, was in revenge accused by her to Proetus her husband, as having attempted to corrupt her. Proetus not willing to violate the laws of hospitality by slaying him in his own house, wrote letters to Jobates, king of Lycia, the father of Sthenoboea, and sent them by the hand of Bellerophon, stating his crime, and desiring Jobates to put him to death. To meet the wishes of his son-in-law, and keep his own hands innocent of blood, he sent him with a small force against a very warlike people called the Solymi; but, contrary to all expectation, he not only escaped with his life, but gained a complete victory over them. He was afterwards sent upon several equally dangerous and hopeless expeditions, but still came off with success; and to reward him Jobates gave him one of his daughters to wife, and a part of his kingdom. Sthenoboea, hearing this, through rage and despair killed herself.
I have given this history at large, because many have thought it not only to be parallel to that of Uriah, but to be a fabulous formation from the Scripture fact: for my own part, I scarcely see in them any correspondence, but in the simple circumstance that both carried those letters which contained their own condemnation. From the fable of Bellerophon came the proverb, Bellerophontis literas portare, "to carry one's own condemnation".

And it came to pass in the morning,.... When David was informed that Uriah did not go to his own house, but slept with his servants, Satan put it into his head and heart to take the following wicked and cruel method:
that David wrote a letter to Joab, and sent it by the hand of Uriah; to have him cut off by the sword of the enemy. If Uriah suspected David's criminal conversation with his wife, he was so true and trusted a servant to him, that he would not open his letter to Joab, which had he, it would have betrayed the base design. No one that knows the story of Bellerophon can read this without thinking of that, they are so much alike; and indeed that seems to be founded upon this, and taken from it with a little alteration. Bellerophon rejecting the solicitations of Sthenobaea, who was in love with him, she prevailed upon her husband Praetus to send letters by him to Jobates (a name similar to Joab), the general of his army, which contained instructions to take care that he was killed; who sent him upon an expedition for that purpose (m).
(m) Apollodorus de Deorum Orig. l. 2. p. 70.

Adulteries often occasion murders, and one wickedness is sought to be covered by another. The beginnings of sin are much to be dreaded; for who knows where they will end? Can a real believer ever tread this path? Can such a person be indeed a child of God? Though grace be not lost in such an awful case, the assurance and consolation of it must be suspended. All David's life, spirituality, and comfort in religion, we may be sure were lost. No man in such a case can have evidence to be satisfied that he is a believer. The higher a man's confidence is, who has sunk in wickedness, the greater his presumption and hypocrisy. Let not any one who resembles David in nothing but his transgressions, bolster up his confidence with this example. Let him follow David in his humiliation, repentance, and his other eminent graces, before he thinks himself only a backslider, and not a hypocrite. Let no opposer of the truth say, These are the fruits of faith! No; they are the effects of corrupt nature. Let us all watch against the beginnings of self-indulgence, and keep at the utmost distance from all evil. But with the Lord there is mercy and plenteous redemption. He will cast out no humble, penitent believer; nor will he suffer Satan to pluck his sheep out of his hand. Yet the Lord will recover his people, in such a way as will mark his abhorrence of their crimes, to hinder all who regard his word from abusing the encouragements of his mercy.

URIAH SLAIN. (2-Samuel 11:14-27)
David wrote a letter to Joab, and sent it by the hand of Uriah . . . Set ye Uriah in the forefront of the hottest battle--The various arts and stratagems by which the king tried to cajole Uriah, till at last he resorted to the horrid crime of murder--the cold-blooded cruelty of despatching the letter by the hands of the gallant but much-wronged soldier himself, the enlistment of Joab to be a partaker of his sin, the heartless affectation of mourning, and the indecent haste of his marriage with Bath-sheba--have left an indelible stain upon the character of David, and exhibit a painfully humiliating proof of the awful lengths to which the best of men may go when they forfeit the restraining grace of God.