Genesis 30:41 Kabbalah

וְהָיָ֗ה בְּכָל־יַחֵם֮ הַצֹּ֣אן הַמְקֻשָּׁרוֹת֒ וְשָׂ֨ם יַעֲקֹ֧ב אֶת־הַמַּקְל֛וֹת לְעֵינֵ֥י הַצֹּ֖אן בָּרֳהָטִ֑ים לְיַחְמֵ֖נָּה בַּמַּקְלֽוֹת׃

And it came to pass, whensoever the stronger of the flock did conceive, that Jacob laid the rods before the eyes of the flock in the gutters, that they might conceive among the rods;