BT BB 6a(30) :אחזיק להורדי ל^א^ אחזיק לכשורי לכשורי אחזיק להורדי‏ : one who acquired the right (to place) reed mats (on his neighbor's wall or roof) did not acquire the right for beams; for beams he acquired the right for reed mats
See the entire entry for hurdā n.m. reed mat