汗牛充栋（汗牛充棟）　

◎ 汗牛充栋 hànniú-chōngdòng

[enough books to make the ox carrying them sweat or to fill a house to the rafters—an immense number of books] 形容书籍存放很多。用牛运输,牛累得出汗;书堆满屋子,顶到栋梁

又有徒党传习,日不 暇给,又其书汗牛充栋。——宋· 陆九渊《与林叔虎书》