7189 seems to be another leveling layer beneath 7184 and 7166, because of its relative position below the southern threshold of room 4. The difference between this possible leveling layer and 7184 is that 7189 might have been deposited to cover and level the drain, due to the fact that 7189 covered the drain running north-south and continued on both sides of the drain. So, 7189 might have been a preparation for 7184 and/or7166.