Biblical Context:
Moses, a central figure in the Old Testament, is often depicted as a leader who intercedes on behalf of the Israelites. His role as a mediator between God and His people is crucial, especially during times of crisis. The phrase "Moses cries out to the LORD" encapsulates several instances where Moses, faced with challenges, turns to God for guidance, intervention, and mercy.

Key Instances:

1. The Red Sea Crossing (Exodus 14:15):
As the Israelites stood trapped between the Red Sea and the pursuing Egyptian army, they were filled with fear and doubt. Moses reassured them of God's deliverance, and in response to the situation, he cried out to the LORD. The LORD instructed Moses to stretch out his hand over the sea, parting the waters and allowing the Israelites to cross on dry ground. This miraculous event demonstrated God's power and faithfulness in response to Moses' plea.

"Then the LORD said to Moses, 'Why are you crying out to Me? Tell the Israelites to go forward.'" (Exodus 14:15)

2. The Bitter Waters of Marah (Exodus 15:23-25):
After crossing the Red Sea, the Israelites traveled through the desert and found no water. When they finally arrived at Marah, the water was bitter and undrinkable. The people grumbled against Moses, and he cried out to the LORD. God showed him a piece of wood, which Moses threw into the water, making it sweet and drinkable.

"So he cried out to the LORD, and the LORD showed him a log. When he cast it into the waters, they were sweetened." (Exodus 15:25)

3. The Battle Against the Amalekites (Exodus 17:8-13):
When the Amalekites attacked the Israelites at Rephidim, Moses instructed Joshua to choose men to fight. Moses, along with Aaron and Hur, went to the top of a hill with the staff of God. As long as Moses held up his hands, the Israelites prevailed. When he grew weary, Aaron and Hur supported his hands, ensuring victory. Though not explicitly stated as a cry, Moses' actions and reliance on God during the battle reflect his continual dependence on divine intervention.

4. The Incident of the Golden Calf (Exodus 32:11-14):
While Moses was on Mount Sinai receiving the Law, the Israelites made a golden calf to worship. God's anger burned against them, and He threatened to destroy them. Moses interceded, crying out to the LORD to spare His people, reminding God of His promises to Abraham, Isaac, and Jacob. The LORD relented from the disaster He had planned.

"But Moses sought the favor of the LORD his God, saying, 'O LORD, why does Your anger burn against Your people, whom You brought out of the land of Egypt with great power and a mighty hand?'" (Exodus 32:11)

5. The Complaint of the People (Numbers 11:10-15):
The Israelites complained about their hardships and the lack of meat. Overwhelmed by the burden of leadership, Moses cried out to the LORD, expressing his frustration and inability to bear the people's complaints alone. God responded by providing quail for the people and appointing seventy elders to assist Moses.

"So Moses asked the LORD, 'Why have You brought this trouble on Your servant? Why have I not found favor in Your sight, that You have laid the burden of all these people on me?'" (Numbers 11:11)

Theological Significance:
Moses' cries to the LORD highlight the importance of prayer and reliance on God in times of need. His intercessions demonstrate a deep relationship with God, characterized by trust, honesty, and a commitment to the well-being of the people he leads. These instances serve as a reminder of God's responsiveness to the prayers of His faithful servants and His willingness to act on behalf of His people. Moses' example encourages believers to approach God with confidence, knowing that He hears and answers the cries of His children.