Question: When the Israelites complained to Moses about being in the desert without food and God sent manna and quail, why didn’t they eat the meat of the herds that went with them?
Answer: When Israel left Egypt, they had provisions. They had dough and kneading troughs. They had much riches which the Egyptians gave them. The Egyptians just wanted them to go! You can read this in Exodus 12:34-36.
You will find the Israelites complained often! When God took them toward Canaan, He could have taken them a shorter way; but, He knew if they saw the warlike Philistines who inhabited the coast—they would run back to Egypt! (Exodus 13:17,18).
There was no problem about food. God was going to take care of them. He wanted them to learn to depend on Him. He provided them bread in the morning and meat for their evening meal,
"...Behold, I will rain bread from heaven for you; and the people shall go out and gather a certain rate every day, that I may prove them, whether they will walk in my law, or no." - Exodus 16:4
"...At even ye shall eat flesh, and in the morning ye shall be filled with bread; and ye shall know that I am the LORD your God (12). ...And it came to pass, that at even the quails came up, and covered the camp: ..." - Exodus 16:12, 13
They even could have bought goods along the way.
"Thou shalt sell me meat for money, that I may eat; and give me water for money, that I may drink: ..." - Deuteronomy 2:28a
The reason they did not eat their flocks and herds: There was not enough for all. (See Numbers 11:21,22).
"And Moses said, The people, among whom I am, are six hundred thousand footmen; and thou hast said, I will give them flesh, that they may eat a whole month. (22) Shall the flocks and the herds be slain for them, to suffice them? or shall all the fish of the sea be gathered together for them, to suffice them?" - Numbers 11:21-22
"600,000" footmen times the average family of four means there were approximately 2,400,000 Israelites wandering in the wilderness. If they had eaten all their animals, they would have had no milk, cheese, beasts of burden to carry or pull wagons, or breeding stock when they got to Canaan. Joshua 5:12 tells us the manna ceased when they ate of the old corn of the land upon arriving.
We Christians can be sure; since our God sustained 2,400,000 complaining Israelites in the wilderness for 40 years, He can take care of us!
"Casting all your care upon him; for he careth for you." 1 Peter 5:7