Proverbs 31:18
"She perceiveth that her merchandise is good: her candle goeth not out by night."
Cross References (ranked by relevance)
1 Thessalonians 2:9
For ye remember, brethren, our labour and travail: for labouring night and day, because we would not be chargeable unto any of you, we preached unto you the gospel of God.
Psalm 127:2
It is vain for you to rise up early, to sit up late, to eat the bread of sorrows: for so he giveth his beloved sleep.
Genesis 31:40
Thus I was; in the day the drought consumed me, and the frost by night; and my sleep departed from mine eyes.