וַתֹּאכַ֙לְנָה֙ הַפָּר֔וֹת הָרַקּ֖וֹת וְהָרָע֑וֹת אֵ֣ת שֶׁ֧בַע הַפָּר֛וֹת הָרִאשֹׁנ֖וֹת הַבְּרִיאֹֽת׃
And the lean and ill-favoured kine did eat up the first seven fat kine.
Read kabbalistic (mystical) interpretation of Genesis 41:20: and classical mystical sources.