E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A notion long prevailed in this country that it augured ill for a matrimonial alliance if the bride did not weep profusely at the wedding.
As no witch could shed more than three tears, and those from her left eye only, a copious flow of tears gave assurance to the husband that the lady had not plighted her troth to Satan, and was no witch.