Faced with Laban's deceitful removal of all the speckled and spotted sheep from the flock, Jacob is forced to create a reality where solid-colored animals will give birth to patterned offspring [הדר זקנים]. To achieve this, he crafts wooden rods, peeling away sections of the bark to expose the white layer beneath [אבן עזרא, מחוקקי יהודה, חתם סופר]. This specific mixed pattern of exposed white wood and dark bark is deliberately designed to prevent Laban from later making false claims about the ownership of the newborns [חתם סופר]. Jacob then firmly drives these rods into the earth, ensuring they stand entirely stable on their own [רש"י, גור אריה, ביאור יש"ר, בכור שור].
He strategically places these rods in the dug-out water troughs, precisely where the running water flows into the pools [רד"ק, שד"ל, רש"י, מזרחי, ברכת אשר]. Jacob chooses the watering area because drinking time is a period of rest and gathering for the flock, in stark contrast to the scattered and constant movement of grazing [בכור שור]. By positioning the rods directly in front of the animals, Jacob leverages a natural phenomenon regarding the animal's imagination. Whatever visual impression is etched into an animal's mind during mating directly influences the physical appearance of its offspring [ספורנו, רבנו בחיי]. As the flocks gather to drink from both sides of the trough, the striking image of the peeled rods in the center captures their complete attention [מלבי"ם, שטיינזלץ].
The presence of the rods immediately stimulates the flocks to mate as they arrive at the water. The simultaneous reaction of both sexes plays a crucial role in this process: the females startle and recoil backward at the sight of the unfamiliar protruding rods, positioning them perfectly for the males to mount them at that exact moment [אבן עזרא, רד"ק, שד"ל, רש"י, ביאור יש"ר, חזקוני]. Conversely, a different approach suggests a purely miraculous occurrence where the water itself transformed into seed within the animals' bodies, allowing them to conceive simply by drinking, entirely without the males [רש"י, מזרחי, ברכת אשר].
Despite his elaborate preparations, Jacob does not rely on a mere natural trick, as God had already assured him of success in a prophetic dream. His physical actions are necessary for two distinct reasons. First, they create a natural vessel through which the divine miracle can manifest, much like prophets who perform physical, symbolic acts to anchor their prophecies in reality. Second, the natural appearance of his strategy conceals the divine intervention from Laban and his men, protecting Jacob's miraculous success from the evil eye [רבנו בחיי, מלבי"ם, נחלת יעקב]. From this entire episode, commentators draw a profound conclusion regarding human nature: if creatures lacking intelligence are so deeply shaped by what they see and think during mating, a human being must certainly strive to elevate and purify their thoughts during moments of intimacy [רבנו בחיי].