BT BM 116b(33) :מלבנא רויחא‏ : a wide brick kiln
See the entire entry for malbān, malbānā n.m. brick mold

BT BM 116b(33) :למלבנא רויחא‏ : for (bricks made in) a wide brick mold
See the entire entry for rəwīḥ adj. full, wide