Comentario citado sobre Números 7:21

Rather, this refers to nothing other than burial, that they [the Patriarchs] would receive their portion to have a burial place in the Land [of Israel]. This is because all those who die in the Land of Israel will be the first to live again in the future, as will be explained with God’s help in Parshat Va’era (6:3). However, their descendants received their portion also during their lifetime in this world, while the Patriarchs specifically [received their portion] only after death, as they will be resurrected first. Therefore, the Holy One Blessed be He showed him in this vision: a heifer corresponding to Abram, as it is said about him And Abraham ran to the cattle (Genesis 18:7). And a goat corresponding to Jacob, who placed goat skins on his neck. And a ram corresponding to Isaac, who had a ram offered in his place. And so Rashi explained in Parshat Naso regarding the princes’ offerings (Numbers 7:21). And the turtledove and young pigeon correspond to Israel. And he cut them in half — this hints that these three Patriarchs specifically after being cut, meaning after death, would receive their portion in the Land, for those who die in the Land of Israel will live first, but not during their lifetime. But he did not cut the bird — because Israel, who are compared to the turtledove and young pigeon, will come to the Land alive. For in this, the Holy One Blessed be He showed him who would go to the Land and in what manner the Patriarchs would have a portion in the Land — which would be after being cut and death, meaning after their sun sets in this world, when the sleep of death falls upon them. This is what is meant by When the sun was setting, a deep sleep fell upon Abram, as it is said Before the sun darkens (Ecclesiastes 12:2). This indicates that when Abram sleeps and dies, then he will receive his portion in the Land, but not now, for the iniquity of the Amorites is not yet complete. And the Children of Israel would be those who enter the Land after Abram’s sun had set and the sleep of death [had come], as mentioned.

וגם את הצרעה, “and also the hornet,” etc.; Remember that miracles occur on two levels, so-called “open” (supernatural) miracles, i.e. visible manifestations of G’d interfering with the laws of nature; secondly there are the so-called “hidden” miracles (natural) which are no less miraculous although we do not witness overt interference with the laws of nature. In the previous verse G’d referred to the first category of miracles, the ten plagues, etc., in which G’d demonstrated His mastery over the forces of the universe, the laws of nature.
Now the Torah, i.e. Moses, turns his attention to the occurrence of “hidden” miracles such as swarms of hornets which occur at regular intervals, almost like rain. Seeing that neither rainfall nor swarms of hornets are the result of changes in the laws of nature they are not regarded as miracles. This is why the Torah introduces this element with the word וגם, “and also,” to say that in addition to the supernatural miracles mentioned above there will also be natural forces such as the hornet. The fact that G’d employs a tiny insect to drive out the powerful people of Canaan is surely enough of a miracle to register with the people who observe this. Therefore — לא תערוץ מפניהם, “You shall not be afraid of them (the inhabitants, not the hornets).” The only One you shall be afraid of is the Lord your G’d Who dwells among you. (The author suggests reading the first 6 words in verse 21 together).

ויכוסו ההרים, “the mountains were covered (with water) hence what follows: ויגוע כל בשר “all flesh perished.” (verse 21) There was no place left to take refuge from the water.