Source and decoding
באותה שעה למדתי ממנו שלשה דברים: למדתי שאין נכנסין לחורבה, ולמדתי שמתפללין בדרך, ולמדתי שהמתפלל בדרך מתפלל תפלה קצרה.
At that time I learned three things from him: one does not enter a ruin, one prays on the road, and one praying on the road offers a short prayer.
Rabbi Yosei describes Elijah correcting his choice of prayer location. Wanting to avoid interruption does not justify entering a ruin. The narrative yields three conclusions in its setting; the ensuing discussion considers suspicion, collapse, and harmful forces.