Tanach · Rishonim on Tanach · Ibn Ezra · Torah
Ibn Ezra on Numbers 10:2/אבן עזרא על במדבר י׳:ב׳
אחצוצרת. שם הפועל בחסרון הצד"י בקריאה ואם הוא כתוב:
1MAKE THEE TWO TRUMPETS OF SILVER. Chatzotzerot (trumpets) is a noun. In its verbal form, one of the tzadis is not pronounced even though it is written.1 (did blow) in I Chron. 15:24. Machtzerim is spelled with two tzadis. However, only one of them is pronounced.
בלמקרא. שם הפועל וכן ולמסע או הוא שם והטעם לעת מקרא ולעת מסע והראשון נכון בעיני:
2FOR THE CALLING. Le-mikra (for the calling) is an infinitive. The same applies to u-le-massa (and for causing to set forward). On the other hand, they might be nouns. In this case, the word le-mikra (for the calling) means at the time of calling, and le-massa (and for causing to set forward), at the time of journeying.2 The first interpretation appears correct to me.