1 Chronicles 22
(David exhorts Solomon)

Right away in this chapter we see The Lord denying David not only a form of ministry, but a dream that the David had to build a temple for The Lord. David desired to do this thing, but The Lord had a reason for not letting David build it. Was it because David was not worthy to build it? No, but The Lord has certain people with certain skills that He wants to employ for His glory. If The Lord denies us something we wanted and gives that thing to someone else, we should rejoice for them and with them. In this situation, The Lord gave to Solomon a task of ministry that David wanted. Rather than David getting upset and not wanting to help Solomon, he comes along side him and lends his hand in the ministry without trying to takeover. He exhorts Solomon and encourages him. V.12-13 "Only the LORD give thee wisdom and understanding, and give thee charge concerning Israel, that thou mayest keep the law of the LORD thy God.
Then shalt thou prosper, if thou takest heed to fulfil the statutes and judgments which the LORD charged Moses with concerning Israel: be strong, and of good courage; dread not, nor be dismayed." David is encouraging Solomon to do this thing that The Lord has asked, and to take courage because it is the lords will he will be accomplishing. There is no place more encouraging than to be in the lords will.
Application: realize that The Lord will speak to me through other people and heed His word through them.
If someone receives something I wanted, I will rejoice with them. The Lord has a different plan for me.  

1 chronicles 21:27
 And the LORD commanded the angel; and he put up his sword again into the sheath thereof.

Mercy is all about not getting what we deserve. Even when we blow it and wrong The Lord with our sin, a repentant heart will open the floodgates of mercy and grace. True repentance for our sin will bring us to our knees and cause us sorrow. We will, when truly repentant, accept full responsibility for our sin. This is just the thing that David did in the verses surrounding this one. He was in a particularly dark time in his life where he had sinned against The Lord and caused the death of 70,000 Israeli men. He knew he had sinned and for three days watched a mighty angel of The Lord massacring his people. Then David came before the lord on behalf of himself in repentance asking The Lord to punish his house, but not the people. A god leader will, at all costs, never want his followers to suffer because of his poor decisions. He will take responsibility with boldness and conviction. Then, when David obeyed The Lord and sacrificed, the angel was commanded to relent. David did not get the punishment he deserved for his sin on behalf of serving a merciful God.The Lord is merciful and anyone who says otherwise is in denial of the sin in this world. I think I often do not take sin as seriously as I should, because when I read the Old Testament in general, I see the lords utter hatred for it.
Application: pray for a greater conviction when I sin.

1 chronicles 11:1-3
Then all Israel gathered themselves to David unto Hebron, saying, Behold, we [are] thy bone and thy flesh. And moreover in time past, even when Saul was king, thou [wast] he that leddest out and broughtest in Israel: and the LORD thy God said unto thee, Thou shalt feed my people Israel, and thou shalt be ruler over my people Israel. Therefore came all the elders of Israel to the king to Hebron; and David made a covenant with them in Hebron before the LORD; and they anointed David king over Israel, according to the word of the LORD by Samuel.

As a young man, I do not imagine David connected his role as a shepherd with preparing him to lead the nation of Israel and become the greatest king the world has ever seen. All David did was be faithful to watch his sheep and faithful to worship The Lord. However insignificant it may have seemed to him at the time, The Lord saw great significance. The Lord took David, a shepherd of sheep, and made him the shepherd of His nation. The Lord was preparing David for what He knew he would be long before anyone else even had a clue. The Lord was faithful to prepare David for what he would one day be because David was faithful to serve The Lord in the present.
Jeremiah 1:4-5
 Then the word of the LORD came unto me, saying,
Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, [and] I ordained thee a prophet unto the nations.