In Parashat Naso, the verse says that כִּֽי־מִנְחַ֤ת קְנָאֹת֙ ה֔וּא (Bamidbar 5:15) in the masculine form, however a few pesukim later we hear that מִנְחַ֥ת קְנָאֹ֖ת הִ֑וא (Bamidbar 5:18) in the feminine form. Why is the Torah inconsistent? Is a מִנְחַת קְנָאֹת masculine or feminine?
The words מנחת קנאת are both feminine and therefore if they are the subject that הוא is referring to then הוא should be vowelized הִוא.
Thus we can put aside the second הוא because it is clearly understandable.
The first הוא, being vowelized הוּא, seems abberant at first, until one carefully studies the beginning of the verse. The verse says that the man shall bring his wife's קרבן, and "he shall not pour on it (עליו) oil nor put on it (עליו) frankincense." The verse is thus already using a male pronoun, not in reference to the subject מנחת קנאת but rather to the word קרבן.
Therefore, when one reaches the next clause of the verse, "כי מנחת קנאת הוּא," one realizes that the male pronoun is referring to the same male subject, קרבן. That is, this verse is saying that the קרבן is a מנחת קנאת.