John Calvin Commentary Genesis 30:35

"And he removed that day the he-goats that were ringstreaked and spotted, and all the she-goats that were speckled and spotted, every one that had white in it, and all the black ones among the sheep, and gave them into the hand of his sons;" — Genesis 30:35 (ASV)

And he removed that day. From this verse, the terms of the agreement are known more certainly.

Laban separates the sheep and goats marked with spots from the pure flock—that is, from the white or black ones—and entrusts these to his sons to be fed, placing a three-day journey between them and the rest to prevent indiscriminate breeding from producing multi-colored offspring.

It follows, therefore, that in the flock Jacob fed, nothing remained but animals of a single color. Consequently, only a faint hope of gain remained for the holy man, while every provision was made for Laban’s advantage.

It also appears, from the distance at which Laban kept his flocks apart, that he was as suspicious as he was covetous. For dishonest men are accustomed to measure others by their own standard, which is why they are always distrustful and alarmed.