BT Ket 21a(38) :סבירא ליה איעביד ^ל^רווחא למילתא כי היכי דל׳ ליפסדוה יתמי‏ : he had thought: I should make extra space in the matter so that the orphans do not lose
See the entire entry for rwāḥ, rwāḥā v.n. space; comfort