Or HaChaim on Numbers 10:11/אור החיים על במדבר י׳:י״א

1 בשנה השנית בחדש השני, in the second year in the second month, etc. In this instance the reason the Torah mentions the year before mentioning the month of the year was in order to establish a linkage between the paragraph describing the cloud lifting to the exact date on which this event occurred, i.e. on the twentieth of the month. [According to our author this is the preferred manner in which such matters are to be described. Ed.]