This artwork from Iran depicts 2 deities kneeling beside the sacred tree, the same tree that Nisroch is depicted as watering with his bucket of water. They have a very similar stance to Nisroch, similar clothes and body type, except for no eagle head. This shows significance to the sacred tree, a tree that historians refer to as the “tree of life.” Nisroch is always depicted as watering the tree, and here it looks like they are either tending to it or worshipping it or praying to it. This piece is a supporting document to Nisroch.
Image Credit: http://www.sacred-texts.com/ane/mba/mba20.htm