Genesis 30:38

ויצג AND HE SET — In the Targum it is rendered by ודעיץ which signifies in the Aramaic language sticking in and inserting. It occurs many times in the Talmud: (Shabbat 50b) “if he stuck it in (דצה) and pulled it out”; (Chullin 93b) “he stuck (דץ) something into it”, where דצה is the same as דעצה, being really a contracted form of it. ברהטים IN THE GUTTERS — in the currents (מרוצות) of water running in the trenches made in the ground to water the sheep there (רהט is the Aramaic of רוץ). אשר תבאנה WHERE THE FLOCKS COME TO DRINK etc. — In the currents whither the sheep come to drink, there did he set the rods in front of the sheep. ויחמנה AND THEY CONCEIVED — The female animal saw the rods, it was startled at the sight of them and recoiled; its mate then pairing with it, it afterwards gave birth to young marked similar to the rods (Genesis Rabbah 73:10).

וַיַּצֵּ֗ג אֶת־הַמַּקְלוֹת֙ אֲשֶׁ֣ר פִּצֵּ֔ל בָּרְהָטִ֖ים בְּשִֽׁקְת֣וֹת הַמָּ֑יִם אֲשֶׁר֩ תָּבֹ֨אןָ הַצֹּ֤אן לִשְׁתּוֹת֙ לְנֹ֣כַח הַצֹּ֔אן וַיֵּחַ֖מְנָה בְּבֹאָ֥ן לִשְׁתּֽוֹת׃

And he set the rods which he had peeled before the flocks in the gutters in the watering troughs when the flocks came to drink, that they should conceive when they came to drink.