Latin frequently omits direct object pronouns (though elementary textbooks only manage to fret about omitted *subject* pronouns) -- so if this is from a Christian context, we supply "him" (as my rendition presumes), if an Earth-Goddess context, "her", and if a polytheism context, "them". I presume a typo, translating MAGNIFICATE ("make great") rather than MAGNIFICAT ("she/he makes great"). ET functions adverbially, since all the imperatives are plural.