Genesis 1:23; Genesis 30:17; Genesis 47:24

23 There was evening and there was morning, a fifth day.
17 God gave heed to Leah, and she conceived and bore Jacob a fifth son.
24 "At the harvest you shall give a fifth to Pharaoh, and four-fifths shall be your own for seed of the field and for your food and for those of your households and as food for your little ones."