The moment for making a sacrifice is when you receive more value than the value you give.
Explanation:
To sacrifice is giving up something very important to receive something more valuable, or someone worth sacrifice. Making a sacrifice is usually related to some other person who influences in making decisions.
People who sacrifice to receive something greater don’t regret sacrificing, they look at that as another path they have chosen and they are happy with the result.
This is an example of a simile, a comparison between two things using the words "like" or "as." "Gloomy as the night" is the simile here, since his sadness is being compared to nighttime.