Ab is the Egyptian concept of the heart-soul, the principle of seven souls believed to be carried in a life. It was believed to be a drop from the heart of the mother of a child at conception. It was typically portrayed as a person who is weighed by the goddess Maàt after death. The other souls were aakhu , ba, ka, khaibut , khat, and ren.

Ab (אָב, Standard Hebrew Av, Tiberian Hebrew ʾĀḇ; from Akkadian abu) is also the eleventh month of the ecclesiastical year and the fifth month of the civil year on the Hebrew calendar. The name is Babylonian in origin and appeared in the Talmud around the 3rd century. This is the only month which is not named in the Bible. It is a summer month of 30 days.

Folklore associated with the month included the belief that crossing a river on the twentieth day would cause sickness and that eating the flesh of a pig on the thirtieth day caused boils.

Holidays in Av

• Tisha B'Av - Av 9
• Tu B'Av - Av 15