“תרעו אל ובנביאי במשיחי תגעו אל”
Simply, the word “nevi’ai” is a term for our Avos, Avraham Yitzchak and Yaakov, who were Nevi’im, and the passuk comes to tell us that HaKadosh Baruch Hu guarded over them and did not allow anything bad to happen to them. But Chazal explain (Shabbos 119b, based on Rashi ibid ad loc. Ubenevi’ai) that this passuk warns not to harm the talmidei chachamim, and in their words “nevi’ai” is a term for talmidei chachamim, as it says (Tehillim 90:12): “U’Navi levav chochmah.”
In light of this, the Ben Ish Chai wrote that the passuk “Ubenivi’ai al tare’iu” is said as an explanation and expansion of the warning of “al tig’u bemeshichai” which was said before that, in which the passuk warns not to touch the “tashbar” and explains: When a child sees that a talmid chachaim is being degraded and offended, the value of the sages diminishes in his eyes, and therefore, he loses the desire to learn diligently and to grow up to be like them. This is what the passuk says: In order to fulfill the warning of “al tig’u bemeshichai” you have to be strict to fulfill the warning of “ubenivi’ai al tare’iu”. That if they see the talmidim who honor and elevate talmidei chachamim, then they will want to toil in their learning and grow up to be like them. (Ben Yehoyada, Shabbos ibid)
