Fake Sutras are No Basis for Reference
This statement is from the text of Great Five Turbidity Sutra, quoted in the Forest of Gems in the Garden of the Dharma. However, if one searches through the table of contents for each section of the Great Treasury of Sutras—scroll 4 and 18 of Kaiyuan Descriptive Catalogue and scroll 7 of the Falsehood Masquerading as Truth Record in the Specific Record, the above contents all consider the source on which this statement was based as a false sutra. Furthermore, this passage and similar context cannot be found within the Indian sutras and abhidharma of the Great Treasury of Sutra. Thus, this type of statement has no basis for reference.
The Key Isn't in "Laity" But Whether They are Fully Qualified as Spiritual Teachers
In answering the question, "Can monastics have a lay person as their spiritual teacher?", we have already referenced texts from sutra, vinaya, and abhidharma, as well as quotations and conducts of historical Buddhist masters. They all clearly state that a monk can study the teachings from a lay person. The rumours on the street that they believe "a monk studying from a lay person" must represent the chaos associated with the degenerate age has no stance, because this was already a common occurrence during Buddha's time. This practice is acknowledged within the sutras and does not only take place during the degenerate age. Furthermore, the emphasis of whether a lay person can be the spiritual teacher of monastics should be on whether the lay person who is providing the teachings fully possesses the qualities presented in the scriptures, as well as whether the student has committed himself to learn from the teacher. The emphasis shouldn't be on the lay status of the teacher. If the above conditions are met, not only does this not signify the chaos of the degenerate period, rather, if master and student abide by the teachings, this represents the upcoming splendor for an era when the teachings will flourish.