You can read about the first in 2 Kings 2.
Elisha was mentored by the prophet Elijah, a man of God who performed many miracles. Both Elisha and Elijah knew one day that God was about to take Elijah up to heaven. Not only that, but the sons of the prophets of the local areas knew. They asked Elisha, "Don't you know your master is going to be taken away from you today?"
Elisha knew. He told the sons of the prophets to be quiet. Then he stuck to Elijah like glue. I believe he loved his mentor and wanted to be like him. That's why he asked Elijah for a double portion of his spirit.
Elijah couldn't grant that; but he knew that God could. So he told Elisha that if he saw him go to heaven, he'd receive his request. (2 Kings 2:9-12 ESV)
When they had crossed, Elijah said to Elisha, “Ask what I shall do for you, before I am taken from you.” And Elisha said, “Please let there be a double portion of your spirit on me.” And he said, “You have asked a hard thing; yet, if you see me as I am being taken from you, it shall be so for you, but if you do not see me, it shall not be so.” And as they still went on and talked, behold, chariots of fire and horses of fire separated the two of them. And Elijah went up by a whirlwind into heaven. And Elisha saw it and he cried, “My father, my father! The chariots of Israel and its horsemen!” And he saw him no more.How do I know that Elisha loved Elijah? His reaction when Elijah is taken away tells us.
Then he took hold of his own clothes and tore them in two pieces.
When Elisha succeeded Elijah, he used Elijah's cloak to hit the water of the river so it would part and he could go through on dry land. Immediately after that, he used salt to heal the spring of water so that no death or miscarriage would come from it any more. God did grant Elisha a double portion of His Spirit, and He used Elisha to perform twice as many miracles as did Elijah. There was to be no mistake: Elisha was God's prophet.
But some young men didn't think so. They were rebellious, idolatrous youngsters who came out to mock the prophet of God. "Go up, you baldhead!" they yelled. They were daring Elisha to do as Elijah did. They did not acknowledge the power of God.
So Elisha cursed them in the name of the Lord.
 And he turned around, and when he saw them, he cursed them in the name of the LORD. And two she-bears came out of the woods and tore forty-two of the boys.
(2 Kings 2:24 ESV)
Lest you think that was mean and nasty, consider this. The "boys" were not little boys, but rebellious and idolatrous young men who could have a very negative influence on Elisha's ministry. Elisha didn't choose the consequence of their mockery - he simply cursed them in the name of the Lord, leaving the judgment to God. God wisely chose to take those young men out of the picture, lest they do harm to God's people.
Matthew Henry's Commentary explains:
Observe the miracle of healing the waters. Prophets should make every place to which they come better for them, endeavouring to sweeten bitter spirits, and to make barren souls fruitful, by the word of God, which is like the salt cast into the water by Elisha. It was an apt emblem of the effect produced by the grace of God on the sinful heart of man. Whole families, towns, and cities, sometimes have a new appearance through the preaching of the gospel; wickedness and evil have been changed into fruitfulness in the works of righteousness, which are, through Christ, to the praise and glory of God.
Here is a curse on the youths of Bethel, enough to destroy them; it was not a curse causeless, for it was Elisha's character, as God's prophet, that they abused. They bade him "go up," reflecting on the taking up of Elijah into heaven. The prophet acted by Divine impulse. If the Holy Spirit had not directed Elisha's solemn curse, the providence of God would not have followed it with judgment. The Lord must be glorified as a righteous God who hates sin, and will reckon for it. Let young persons be afraid of speaking wicked words, for God notices what they say. Let them not mock at any for defects in mind or body; especially it is at their peril, if they scoff at any for well doing. Let parents that would have comfort in their children, train them up well, and do their utmost betimes to drive out the foolishness that is bound up in their hearts. And what will be the anguish of those parents, at the day of judgment, who witness the everlasting condemnation of their offspring, occasioned by their own bad example, carelessness, or wicked teaching!
The second story I read was that of Miriam. She was Moses' elder sister. In Chapter 11 of Numbers we read that God gave Moses permission to appoint 70 elders to help him, and God demonstrated that His power was on them by giving of His Spirit to them so that they praised and prophesied.
Perhaps Miriam was jealous. After all, she had been by Moses' side and had sung praises to God. She let her discontent with the situation be an excuse to criticize Moses' choice of a wife. She thought that her other brother Aaron deserved some recognition as well, and likely got him to complain, too.
Be sure your sins will find you out. God heard her mutterings, and He summoned the three siblings to the tent of meeting. If you've ever been summoned to the principal's office, or called to a private meeting by your boss, you have an idea of how Miriam must have felt.
And suddenly the LORD said to Moses and to Aaron and Miriam, “Come out, you three, to the tent of meeting.” And the three of them came out. And the LORD came down in a pillar of cloud and stood at the entrance of the tent and called Aaron and Miriam, and they both came forward. And he said, “Hear my words: If there is a prophet among you, I the LORD make myself known to him in a vision; I speak with him in a dream. Not so with my servant Moses. He is faithful in all my house. With him I speak mouth to mouth, clearly, and not in riddles, and he beholds the form of the LORD. Why then were you not afraid to speak against my servant Moses?” And the anger of the LORD was kindled against them, and he departed.
(Numbers 12:4-9 ESV)God defended His prophet. There was to be no murmuring and complaining against him. God set Miriam and Aaron straight. I imagine His voice shook the tent. As soon as He left, Miriam found herself full of leprosy.
Aaron immediately cried out to Moses...
And Aaron said to Moses, “Oh, my lord, do not punish us because we have done foolishly and have sinned.
(Numbers 12:11 ESV)
Moses, a meek and godly man, cried out to God on Miriam's behalf. Like Christ who pleaded, "Father, forgive them," Moses held no grudges against his sister or his brother. It's more painful to be hurt and mocked by those in our family or in our close relationships, so Moses' example is a gracious one that we should follow. We have no cause to punish those who sin against us. Jesus paid the price for their sin; or if they are not saved, they will pay the price in eternity. All we are called to do is to forgive.
God did give Miriam a reprieve; she only had to suffer with the leprosy outside the camp for 7 days. She would have had to present herself to her brother Aaron, the high priest, to be declared clean and be allowed back into the camp. I would imagine it was a very humbling experience for both of them.
So what should we learn from these two stories?
1. Don't mock God's prophets. That principle carries through to the leaders in the Church that God has raised up to preach and to teach His word. Be very careful what you say. Teach your children to respect the Pastor and elders of your congregation. Yes, they are sinners saved by grace, just as you are. But they have been given a high calling and will one day give an account. Honour them.
Let the elders who rule well be considered worthy of double honor, especially those who labor in preaching and teaching.
2. Our ways are not God's ways. We likely wouldn't think of sending a she-bear out to tear up young men. But God knows what is best. We do not know what damage would have been done if those mockers were allowed to live. When we don't understand God's ways, we do well to remind ourselves that "as the heavens are high above the earth, so are His thoughts higher than our thoughts, and His ways higher than our ways."
3. God is merciful. He punishes and restores. He rightly curses a source of water, but then causes His prophet to heal the spring with salt. He rightly gives leprosy to a bitter woman, then causes His prophet to pray for her healing. He will not always strive with us, nor will He be angry forever. He forgives.
May we be like Him.