Question about an aztec ritual

 

I am new to this forum and I was wandering if you can give me some information. I was trying to write a story about aztecs when I suddenly realized that I don't know something of big importance to me. Eagle-warriors (mabye jaguar-warriors too, I am not sure) performed a self-damaging ritual during which they spilled their blood by piercing parts of their body with cactus thorns. Can someone tell me where did they kept the thorns before using them?