《北史·本记·卷二》
屈丐蒸土修筑城池，使之更加坚固，也被我灭掉了，难道在乎城池是否坚固险要吗？
屈丐蒸土筑城，而朕灭之，岂在城也？
Qu Ge steamed the earth to build the city wall, making it stronger, but I also wiped it out. Does it matter whether the city wall is strong and dangerous?