It is a farm fertilizer. When mixed with Diesel fuel it becomes a nitrate OXIDIZER for the explosive DIESEL.
It also makes a handy oxidizer in making rocket fuel.
Mix it with sugar and heat it to cook it to a syrup and pour it in a pipe and when it cools and solidifies you have rocket fuel.
But what you can clearly see is the explosion becomes a detonation. Ammonium nitrate can not detonate unless it is mixed with a fuel, no fuel no detonation.
It was obviously a Hezbollah ammo dump. Being that Lebanon has a long history of rocket attacks on Israel the “news media” is in hyper cover up mode.
NH4NO3 doesn’t become unstable. In fact, to make it, you have to provide serious consideration to the fact that manufacturing it produces prodigious amounts of heat.
To make that bond break, you have to ADD THERMAL ENERGY to get it to go.
It’s an oxidizer, which means you generally need to add something to it (Aluminum or Iron filings), and an initial charge to make it go.
When it DOES go, it doesn’t produce a deep red fireball like it did.
Now, rocket propellant, does. There was a blast in the 80s in Nevada that involved rocket fuel that had the same characteristics, right down to the speed of the shockwave.
AMFO (Ammonium Nitrate mixed with Fuel Oil), is relatively slow to combust compared to other explosives. This blast had a shockwave that was moving.