This ancient tradition has it's origins from Zorostrianism and is still widely practiced today. In Iran, Afghanistan, and Tajikistan when a child returns home after being among strangers, some parents will light a charcoal disk and burn the spalanaey seeds while reciting a poem, actually an ancient Zoroastrian prayer, against the evil eye and directing the smoke around the child. This is done as a protective measure, whether or not it is suspected that the child has been given the eye. The rite consists of an invocation prayer to a deceased but historical king of Persia known as Naqshband, while burning espand/ spalanaey seeds. The word espand refers to a class of Zoroastrian Archangels. It was common that our Zoroastrian forefathers used to pick a patron angel for their protection, and throughout their lives were observing prayers dedicated to that angel. Today whenever we burn espand grains to "espand" ourselves, it is in fact the invocation of blessing of the archangels (Amahraspand or aspand) that our ancestors observed prayers to. In some homes today verses from the Koran are recited instead of that ancient prayer.
Sometimes instead of spalanaey being burned it is just mentioned. For example when a child is sick his or her mother will sometimes wet the child's hair and say " spalanaey di sum" the Pashto phrase to ward off the evil eye. Also when one's beloved says some sweet words to them the other often says " spalanaey di sum" to ward off the evil eye.