Or HaChaim on Exodus 13:19/אור החיים על שמות י״ג:י״ט

1 פקד יפקד אלוקים, "when G'd will surely remember you, etc." The reason the Torah repeats the word פקד is in order to emphasise the manner in which Moses kept faith with the promise made to Joseph by his brothers. The first time the word פקד simply means that G'd will certainly keep His promise to redeem the Israelites. This included only removal of the negative aspects of the Jews' exile. There was, however, also a positive aspect to the bondage, the one described in Genesis 15,14, namely that the Israelites would leave Egypt as wealthy people. According to Bechorot 5 not a single Israelite took less than ninety donkeys' loads of silver and gold out of Egypt. Joseph foresaw that the Israelites' preoccupation with loading the animals with all these valuables were a reason for their leaving his bones behind; this is why he made the brothers swear that even the preoccupation with their newly acquired wealth should not make them forget his bones at that time. In any event Moses was the only one who instead of loading his animals with valuables went in search of Joseph's remains and eventually loaded Joseph's bier on his donkey (compare Shemot Rabbah 20,19). At a later date G'd rewarded Moses by letting him keep the splinters of the precious stones from which he carved the second set of tablets.

2מזה אתכם, "with you from this place." The word מזה does not mean "from here," i.e. that Joseph thought the brothers would have to locate his remains exactly in the place where he made them swear this oath. Joseph used the expression as the reason he asked the brothers to swear such an oath. He considered it as a small repayment of all the favours he had done for the brothers during their stay in Egypt. He went so far as to hint that taking his bones out of Egypt for burial in the Holy Land would compensate for the time when they had separated themselves from their brotherhood with him; the angel had told Joseph in Genesis 37,17 that the brothers נסעו מזה "had departed from זה" (the number 12, symbol for the 12 brothers, compare Bereshit Rabbah 84). Joseph used the words מזה אתכם to indicate that if the brothers would fulfil their oath he would consider them as having re-instated him in their midst. The sin they had committed against him at that time would then have been wiped out. In other words, Joseph would forgive the brothers posthumously, for simply swearing the oath.