Comentario citado sobre Números 15:35

He who desecrates the Sabbath [is stoned], providing that it is an offence punished by “kareth” if deliberate, and by a sin-offering if unwitting. According to Numbers 15:35, one who breaks the Sabbath is punished by being stoned. However, we learn elsewhere that he is stoned only if he is warned prior to the transgression that if he violates the Sabbath in such a manner he will be stoned. Our mishnah teaches that this is true provided that his violation was one which is punished by “kareth” (a death penalty meted out by God) if not warned (but nevertheless committed with intent to break the Sabbath). He also must commit a transgression for which he is obligated to bring a sin-offering if he did it unwittingly (for instance he didn’t know that today was the Sabbath or that this type of work is prohibited). The seventh chapter of Tractate Shabbat lists which types of work one is prohibited from doing on the Sabbath. One who is warned not to do one of these types of work and does so anyway is to be stoned. There are other types of work which are forbidden to do on the Sabbath but are not punished by stoning.

כליל תכלת, entirely of blue wool. I believe that the reason why this garment was totally blue is that seeing that both the ephod’s and the choshen’s function is to evoke the zikaron, the memory of G’d, the m’il, which is the base for the other two garments is also dyed in a colour symbolising memory as we know from the blue strand in the tzitziyot which the Torah describes as evoking the memory of heaven and G’d’s commandments in Numbers 15,35.

כי לו פורש מה יעשה לו, “because it had not been made clear what should be done to him.” This refers to which of the four types of death penalties was applicable to someone committing this type of Sabbath violation. All that was known so far was that deliberate violation of the Sabbath is subject to the death penalty as written in Exodus 31,14. Now G’d clarified: “the man shall be put to death the entire assembly shall pelt him with stones outside the camp” (verse 35).