וַיַּצֵּ֗ג אֶת־הַמַּקְלוֹת֙ אֲשֶׁ֣ר פִּצֵּ֔ל בָּרֳהָטִ֖ים בְּשִֽׁקֲת֣וֹת הַמָּ֑יִם אֲשֶׁר֩ תָּבֹ֨אןָ הַצֹּ֤אן לִשְׁתּוֹת֙ לְנֹ֣כַח הַצֹּ֔אן וַיֵּחַ֖מְנָה בְּבֹאָ֥ן לִשְׁתּֽוֹת׃
And he set the rods which he had peeled over against the flocks in the gutters in the watering-troughs where the flocks came to drink; and they conceived when they came to drink.
Read kabbalistic (mystical) interpretation of Genesis 30:38: and classical mystical sources.