This commercial use
pack is released under a no-attribution, no reselling license. This means:

You can use, modify,
and share these assets as much as you'd like in any project that you charge
money for or use commercially - and you don't have to mention where you got
them. (But I'd appreciate it!) You can alter and modify these assets however
you'd like, but you can't resell those base or modified assets.

For example: You
draw some lava on these potions. Now they're lava potions. You can use those
commercially as much as you want within your maps or projects - but you can't
resell your modifications as individual or packaged assets themselves.