創世記 29:25

ויהי בבקר והנה הוא לאה AND IT CAME TO PASS, THAT IN THE MORNING, BEHOLD, IT WAS LEAH —But at night it was not Leah (i. e. he failed to recognise that it was Leah) because Jacob had given Rachel certain secret signs by which they could at all times recognise one another, and when Rachel saw that they were about to bring Leah to him for the marriage ceremony, she thought, “My sister may now be put to shame”, and she therefore readily transmitted these signs to her (Megillah 13b).

וַיְהִ֣י בַבֹּ֔קֶר וְהִנֵּה־הִ֖וא לֵאָ֑ה וַיֹּ֣אמֶר אֶל־לָבָ֗ן מַה־זֹּאת֙ עָשִׂ֣יתָ לִּ֔י הֲלֹ֤א בְרָחֵל֙ עָבַ֣דְתִּי עִמָּ֔ךְ וְלָ֖מָּה רִמִּיתָֽנִי׃

And it came to pass, that in the morning, behold, it was Le᾽a: and he said to Lavan, What is this thou hast done to me? did not I serve with thee for Raĥel? why then hast thou beguiled me?