You can sit up here because you are smart!

Recently I had the fabulous opportunity to teach another teacher's class. The students came in, perhaps assumed I was a substitute, and were walking around the room, talking, and quite concerned about their hair (hence the bottle of mousse being shared).
As the students continued to come in the classroom, I started assigning seats since most of the students gravitated towards the back of the room. I told two students, "you may sit here and here" to which they asked, "why?" My initial response was "I don't know" and then I followed that up with "you can sit up here because you are smart!" When the next person walked in the room and asked why they were sitting up in the front, one student responded "because she said we're smart." As the class continued, I explained why I was in the class with them and told the students that I only work with smart students. "That's the bottom line - I only work with fabulous, smart students, and your teacher has told me fabulous things about how smart you are - I know you've got great brains!" The class was silent and focused on my every word!
As the lesson continued, I realized this was not going as smoothly as I wanted - I focused on the students who were grasping parts of the lesson but told the students, "I would like to share with you what I am thinking - I want a chance to revise this activity so that next time I am with you, we can all have more success!"