וַיֹּ֥אמֶר יְהֹוָ֖ה אֶל־מֹשֶׁ֥ה לֵּאמֹֽר׃ דַּבֵּ֞ר אֶל־בְּנֵ֤י יִשְׂרָאֵל֙ וְאָמַרְתָּ֣ אֲלֵהֶ֔ם וְעָשׂ֨וּ לָהֶ֥ם צִיצִ֛ת עַל־כַּנְפֵ֥י בִגְדֵיהֶ֖ם לְדֹרֹתָ֑ם וְנָ֥תְנ֛וּ עַל־צִיצִ֥ת הַכָּנָ֖ף פְּתִ֥יל תְּכֵֽלֶת׃
“Hashem said to Moshe saying. Speak to the children of Israel, and tell them that they should make themselves fringes in the borders of their garments throughout their generations, and that they put on the fringe of each border a cord of blue".
See the Ohr Hachaim who asked why it says here "ויאמר ה' אל משה לאמר" while usually it says "וידבר ה' אל משה לאמר"?
He also noted the double language of "דבר אל בני ישראל ואמרת אליהם" - "Speak to the children of Israel, and tell them" [and as the Alschich noted that אמירה denotes soft speech while דיבור denotes harsh speech. So how do they work in tandem?].
He also asked what the meaning of the "ו" is in the word "ועשו" "AND they should make tziztis". What is the "ו" connecting to?
He also asks about the meaning of "לדרתם" - "for the generations". ALL mitzvos are for all the generations??
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It would appear that all mitzvos have either a hidden reason or revealed reason or both but tzitzis are different insofar as that the in the mitzva itself we have a reason, as it says "וראיתם אתו וזכרתם את כל מצוות השם" - We see the tzitzis and remember ALL the mitzvos of Hashem etc. In the Shulchan Aruch [8-20] it says that we should have kavanna when we wear our tzitzis to remember all the mitzvos. The Bach says that since the pasuk gives the reason for the mitzva it must be that having the reason in mind is part and parcel of the mitzva. So we see that besides the מעשה מצוה there is also a fulfillment of וראיתם אותו וזכרתם - seeing and remembering all the mitzvos.
Now we can say that when the pasuk says "דבר אל בני ישראל ואמרת אליהם ועשו" is because "דבר" which is a harsh language refers to the primary obligation to wear tzitzis because if he didn't put tzitzis on his 4 garments he nullified this mitzva and transgressed his obligation. In addition it says "ואמרת" which is a softer tone, and that relates to the lighter obligation of seeing the tzitzis and remembering all the mitzvos which is not critical and not מעכב the mitzva and thus not framed as "דיבור" but rather as "אמירה".
