多谢Englishreader! 我有同感，刚Google了一下：

In seventh heaven: In a state of bliss, as in "John was in seventh heaven when the director praised his speech". Used figuratively since the early 1800s, this term alludes to the dwelling place of God in highest of the seven concentric spheres that surround the earth in the system recognized by both Muslims and ancient Jews.

Forty winks is an English idiomatic noun that can be used in the singular or plural and means: to take a nap for a short period of time (usually not in bed), or to take a short sleep during the day.

Alternative idiomatic sayings such as could not sleep a wink provide the mental picture of a wink being the shortest type of sleep available and "forty winks" therefore gives an indication of an appropriate short sleep. Indeed the saying appears to have developed in relationship to 40 being an indefinite term for a large number that has almost sacred or magical quality. The use of the word 40 is reflected in numerous biblical references for example Moses was on Mount Sinai for forty days and forty nights, Elijah was fed by ravens for forty days, Noah and his animals endured flooding rains for forty days, and then waited another forty days before he opened the window of the ark, and finally that Jesus Christ fasted for forty days, and then was seen forty days after his resurrection.