Genèse 30:41

And it was that whenever the early (prime) sheep conceived, Jakob set the rods in the canals before the eyes of the sheep, that they might conceive before the rods.

THE FLOCKS ‘HAMEKUSHAROTH.’ The correct interpretation of this expression appears to me to be that they are the flocks in which the males follow the females at all times, never leaving them due to their abundant desire, as in the expression, Seeing that his soul is ‘keshurah’ (bound up) with the lad’s soul. This is also found in the language of our Sages: “a swine karuch (clinging) to a ewe;” “clinging to her.” And the offspring born at that time are called hakeshurim after the name of their father.
But many authorities say that keshurim are “the strong ones” whose limbs are firmly attached to each other with a strong tie, as this is the basis of health, while atuphim are “the weak ones” whose soul ‘tithataph’ (fainted) in them, and who have no desire, as in the expression, ‘ha’atuphim’ (that faint) for hunger. Onkelos translated hamekusharoth as the early-bearing sheep, and atuphim as the late-bearing ones, for such is the fact: [the early-bearing sheep are the stronger ones, and the late-bearing ones are weaker].

המקושרות, during the month of Tishrey.

והיה בכל יחם, during all the periods when the animals were in heat, i.e. at the time when they mated; this is in accordance with Onkelos’ rendering of these words. This is the standard translation every time the word occurs.

ויחם, the reason the infinitive mode is used for the word is in order for it to be connected to the preceding word בכל, which is used in lieu of the word שם, “there, wherever.” When the word does not signify any specific time, i.e. either past, present of future, which would limit its application, then the word בכל is appropriate as it also is a totally inclusive word, not allowing for exceptions. The infinitive is therefore absolutely in place. The sheep give birth twice a year, and the Torah now tells us before which of the cycle of births Yaakov positioned the sticks by the troughs. Yaakov positioned the sticks before the first cycle of births which was numerically much smaller, because Lavan did not bother to check on what was going on during that period. Before the second birthing during that year Yaakov did not position the sticks in order to arouse the imagination of the animals because at that time Lavan would come to inspect his sheep and if he had discovered that Yaakov was using these sticks this would have resulted in a quarrel between them, and Lavan would have stolen from him whatever he thought should be his. Even though Yaakov had never positioned the sticks in front of any animals that were Lavan’s, as I explained on verse 37, in the name of my late father, Lavan would have argued that just as Yaakov placed this sticks before his own animals so he would presumably do also when watering Lavan’s flocks.

The meaning of the words המקושרות, הקשורים and העטופים, as well as the word ובהעטיף, is in accordance with the way Onkelos translates them, descriptions of the time cycle during which certain animals would give birth. My late father of blessed memory, explained that the agreement for the first year called for the result of the first birthing to be Yaakov’s, whereas the result of the second birthing would be Lavan’s.

המקושרות, “the sturdier ones;” According to Rashi the meaning of the word is: מבכירות, “the ones liable to give birth early in the season because they conceived without difficulties.” Although he attributes this interpretation to Targum Onkelos, he was unable to quote proof, and neither did Onkelos quote proof. I believe that the word is connected to the root: קשר, “knot.” It was the custom in those days to tie a knot to the firstborn animal of each mother, in order to be able to identify these animals later on as they were presumed to be stronger, or at any rate preferred by their owners to those born later. This would prevent them from being confused with animals born by the same mother animal in subsequent years. We know from Genesis 38,28, that the midwife of Tamar also tied a knot to the twin that appeared to be born first from its mother’s womb. The author quotes the Maharam from Rotenburg as saying that in his time fathers also displayed preferences for firstborn sons.