…they remembered not the multitude of Thy mercies; but provoked Him at the sea, even at the Red Sea. – Psalm 106:7

Why did (the Israelites) transgression at the sea so greatly anger the Lord? Was it because it came at the outset of their existence as a nation? They had not gone many days’ journey out of Egypt before they rebelled. They had not yet eaten up the bread they carried in their kneading troughs, and they had scarcely met their first difficulty; and yet they hastened to provoke their God. How could they rebel so soon? They had scarcely reached the Red Sea before they began provoking the Lord with their dishonorable suspicions. Now this Red Sea was the place of their consecration. Here they were “baptized unto Moses in the cloud and in the sea.” Here it was that they said, “He is my God, and I will prepare Him an habitation; my father’s God, and I will exalt Him.” As they stood by that Red Sea which had swallowed up all their enemies, they sang the praises of God and proposed to do great things in His honor. What wonderful obedience they meant to render! And yet they provoked Him there and then. What! will you come up from the waters of your baptism, and go home and provoke God by unholy conversation and ungovernable temper? Can any of you go from the Communion Table into sin? I heard of one who went from the table of the Lord across the street into the public-house. This is too gross. Such conduct grieves holy men, and much more the Holy God. To go from prayer to robbery, from reading the Word to fellowship with ungodly men—this must be terribly provoking to the thrice holy Jehovah. It is as though it were written again, “They provoked Him at the sea, even at the Red Sea.” It is a high crime and misdemeanor to sin in the presence of a great mercy. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2204.cfm