And he answered is literally “And he answered and he said.” The pronoun he refers to Balaam, which NET Bible makes explicit.

Must I not take heed to speak what the LORD puts in my mouth?: This rhetorical question implies an emphatic affirmative assertion. It is literally “[Is] not what the LORD puts in my mouth, it I must take care to speak?” This question is very similar to the final sentence in 22.38 (see the comments there). Most English translations render it in the same way as Revised Standard Version (so New Revised Standard Version, New International Version, Revised English Bible). Many German and Dutch translations have “wild bull” (Luther, De Nieuwe Bijbelvertaling), while French versions frequently have “buffalo” (Bible en français courant, Parole de Vie, La Bible de Jérusalem Nouvelle, Traduction œcuménique de la Bible).

Quoted with permission from de Regt, Lénart J. and Wendland, Ernst R. A Handbook on Numbers. (UBS Helps for Translators). Miami: UBS, 2016. For this and other handbooks for translators see here .