Forty days before the formation of a child a Bath Kol proclaims, "The daughter of so-and-so shall marry the son of so-and-so; the premises of so-and-so shall be the property of so-and-so."
Soteh, fol. 2, col. 1.
Rav Hunna and Rav Chasda were so angry with one another that they did not meet for forty years. After that Rav Chasda fasted forty days for having annoyed Rav Hunna, and Rav Hunna forty days for having suspected Rav Chasda.
Bava Metzia, fol. 33, col. 1.
A female who marries at forty will never have any children.
He who eats black cummin the weight of a denarius will have his heart torn out; so also will he who eats forty eggs or forty nuts, or a quarter of honey.
Tract Calah.
He that cooks in milk the nerve Nashe on a yearly festival, and then eats it, receives five times forty stripes save one, etc.
Baitza, fol. 12, col. 1.
He who passes forty consecutive days without suffering some affliction has received his good reward in his lifetime (cf. Luke xvi. 25).