“Neither.” While confusing at first blush, the angel’s answer makes perfect sense. Joshua asked if he was “for us” or “for” the enemy. The correct answer is “Neither.” God is not “for us,” as if He was following our lead and our agenda. We must be “for Him.”
“bowed low in worship.” The act of worship was demonstrated by bowing low, and so some English versions say “worship” (cp. KJV, ESV, CSB) and some say “bow,” “bow down,” or “bow low” (cp. NASB, NET). The problem with bringing the Hebrew into English is that the bowing down was itself representative of worship, but if the English version reads “worship” the reader misses the fact that the worship was demonstrated by bowing, but if the version reads, “bow down,” the reader misses the fact that the bowing was worship. The REV adds the italics to complete the sense of the Hebrew text and culture. [For more on the “worship” of superiors, see commentary on Matt. 2:2]. This angel was a messenger and agent of God, but was not God. Also, the use of “lord,” here, adoni, (the specifically inflected Hebrew word, not the root word) shows that Joshua did not consider the one he was talking with to be God (see commentary on Psalm 110:1 for the meaning of adoni).