וְיֵ֞שׁ אֲשֶׁר־יִהְיֶ֤ה הֶֽעָנָן֙ מֵעֶ֣רֶב עַד־בֹּ֔קֶר וְנַעֲלָ֧ה הֶֽעָנָ֛ן בַּבֹּ֖קֶר וְנָסָ֑עוּ א֚וֹ יוֹמָ֣ם וָלַ֔יְלָה וְנַעֲלָ֥ה הֶעָנָ֖ן וְנָסָֽעוּ׃
Parfois la nuée demeurait du soir jusqu’au matin, et quand elle se retirait le matin on partait; ou bien un jour et une nuit, et quand elle se retirait, l’on partait.
Rashi
אז ישיר משה THEN SANG MOSES — with regard to the usage of the future ישיר, the meaning is: THEN — i. e. when he saw the miracle it entered his mind that HE WOULD SING a song. Similar is, (Joshua 10:12) “Then Joshua would speak (אז ידבר)”; and similar, (1 Kings 7:8) “and a house he would make (יעשה) for Pharaoh’s daughter”, which signifies “he purposed in his heart that he would make it for her”. So, also, ישיר here signifies: his heart told him that he should sing, and thus did he actually do, as it states, “and they (Moses and Israel) spake as follows, ‘I will sing unto the Lord’”. And in the same way, in the case of Joshua, it means: then (או) — when he saw the miracle mentioned in that narrative — his heart told him (prompted him) to speak, and thus did he actually do, as it is stated, “and he spake before the eyes of all Israel”. The same applies to the Song of the Well (Numbers 21:17) which begins with the words: אז ישיר ישראל, “then would Israel sing”; it expresses the intention quite plainly in the following words, “Come up, O Well — sing ye unto it” (i. e. these words are a call to the people to sing to it after Israel had expressed their intention so to do and are not part of the song itself which begins with the words that follow). With regard to (1 Kings 11:7) אז יבנה שלמה במה our Rabbis explained that He proposed to build a high place for Chemosh but actually did not build it (Sanhedrin 91b). This, too, teaches us that the י as a prefix of the imperfect is used in reference to intention to do a thing. This explanation serves to settle the literal meaning of the text. But so far as its Midrashic explanation is concerned our Rabbis, of blessed memory, said: from here (i. e. from the fact that the future tense is used) we may derive an intimation that the tenet of the Resurrection of the Dead is from the Torah (is alluded to, although only by inference, in the Torah) (Sanhedrin 91b). And thus, also, do they explain in the case of all them (all of the examples quoted) except in the case of that referring to Solomon which they explained in the sense that he purposed to build a high place but did not build it. — One cannot say that this can be appropriately explained in the same way as one explains other passages which are written in the future tense, but which really refer to an immediate action (i. e. to a then present time); for example, (Job. 1:5) “Thus was Job doing (יעשה)”; (Numbers 9:18) “At the command of the Lord were they encamping (יחנו)”; (Numbers 9:20) “And there were occasions when the cloud was (יהיה) upon the tabernacle”, because these were each of them something that was continuously happening, and there is proper to it either the future tense or the past tense (cf. Rashi on Genesis 29:3). But this (אז ישיר and other passages quoted) which happened only at the particular moment mentioned (once and once only), one cannot fittingly explain in this sense (i. e. of continuous action).
Rabbeinu Bahya
A careful analysis shows that 14 of the total of 42 stops were made during the first year of their journeying. Eight more stops are recorded after the death of Aaron which occurred in the 40th year, so that during the 38 years after the sin of the spies until the death of Aaron there were only 20 stops. According to our tradition the “many years” which the Israelites are reported as having remained stationary in Kadesh (Deut. 1,15) were equivalent to the total of the years they journeyed from there, i.e. 19 years. This effectively reduces the period of wanderings or journeying to 19 years during which they broke camp 19 times. There was clearly no human planning at work in the strategy governing these journeys, why else would the Torah describe that sometimes the people would stay in one place for only a single night (Numbers 9,21)? The people never knew for how long the cloud would remain stationary signaling that they were to remain in their present location. All their journeys were determined by G’d’s strategy, not their own or that of Moses.
We may illustrate the matter by means of a parable. A king had a sick child. He took that child from one place to another to find a cure for him. After the father returned from these exhausting trips and the child had been cured, he would remind himself and the child of what happened at each location that he and his sick child had stopped on the way. He would remind his son: ”here we were freezing cold;” “here we were resting comfortably,” “here you suffered from a headache,” etc., etc.
We may illustrate the matter by means of a parable. A king had a sick child. He took that child from one place to another to find a cure for him. After the father returned from these exhausting trips and the child had been cured, he would remind himself and the child of what happened at each location that he and his sick child had stopped on the way. He would remind his son: ”here we were freezing cold;” “here we were resting comfortably,” “here you suffered from a headache,” etc., etc.
Rashi
העלות הענן — Understand this as the Targum does: the departure (more lit., the raising itself). Similar is, (v. 21): תעלה הענן which means “when the cloud raised itself” (departed; in both cases the verbs are Niphal). It would not be correct to have written in these passages ולפי עֲלוֹת הענן and וְעָלָה הענן (the verbs in the Kal), because this would not be an expression denoting departure, but “springing forth” and “rising”, just as, (1 Kings 18:44): “Behold a little cloud as small as a man’s hand rises (עלה) from the sea."