Shahnameh epic, the national-cultural heritage and a documentary evidence of Iranian identity, despite the attempts made by Shahnameh scholars, still has a great number of ideas and symbols requiring profound studies from the viewpoint of ideology, symbology, and lexicology. On the other hand, Shahnameh, since it has been composed in Farsi language, is a rich source of, as well as the key to the permanence of, Farsi Language. If we believe that the social context of the period in which a poet lives will affect dramatically the way a literary work is created and that a poet will be under the influence of the manners and practices of his/her own surrounding area, then there are manners, practices, and minor cultures throughout the province Khorasan, the Great, located in Iran country, which can be studied, collected, and recorded not only to preserve and transfer them to further generations but also to solve the secrets behind a great number of symbols and lexical and semantic complexities found in Farsi texts, whether in verse or in prose; the present article has been written based on the same approach – doing a critical review about a line from the epic Shahnameh based on the manners and practices remaining from ancient times in Khorasan, the Great. The two lines in the story of Rostam and Sohraab, which come into focus in the present study, refer to the words of Gerdaafareed, the Iranian charming heroine, when she finds herself unable to cope with Sohraab in the battlefield and her beautiful hair and face are revealed; she then tries to deceive Sohraab, the honest naïve young hero, with her feminine tricks, calling enchantingly from the top of the castle:"نباشی بس ایمن به بازوی خویش خورد گاو نادان ز پهلوی خویش"“Thou shall not be that safe by thy arm (=power) Stupid cows feed on the milk from their own sides (=teats) ”In this article, first, the second line has been considered from the viewpoint of commentators and Shahnameh scholars; then their opinions have been criticized and evaluated, and, in another part of the article, it has been attempted to reach the correct and appropriate meaning of the two lines based on the current manners and practices of the old traditional farmers and cattlemen in Gonaabaad city. It has been argued that the idiomatic phrase “feed on their teats/sides”, [=“cut their own throat” in English] besides the secondary meaning of harming oneself as the figurative sense of the idiom, has been intended to refer to the meaning developed in mind by the literal image, i.e. the primary meaning; thus, “side” does mean “teat”, besides meaning “from; through”.