Sleep after the second loop in a shell script

Here's the translation of the provided Japanese blog article into English:

When processing redundant items one by one, you may need to sleep after the second loop to avoid doing everything at once.

#!/usr/bin/env zsh

sleep_command=""
for i in {1..3} ; do
    eval ${sleep_command}
    echo ${i}
    sleep_command="sleep 10"
done