The sign on the wall said 'Now wash your hands'.

墙上的牌子上写着“请洗手”。

《牛津词典》

When Dan got to class the next day, he saw a sign on the wall.

第二天，当丹来到教室时，他看到墙上有一块牌子。

youdao

Have you read the sign on the wall which says "No Smoking"?

你读了墙上“禁止抽烟”的告示了吗？

youdao

Speaking to the BBC, Mr Betchley's son, Stuart, said there had been an A4 "nil-by-mouth" sign on the wall above his father's hospital bed.

BBC: Norman Betchley

But according to a report in The Wall Street Journal, the bankers were not allowed to negotiate terms, and were told to sign on for their own good and for the good of the country.

NPR: Federal Plan To Invest In Banks Met With Caution