The first quotation in this section, "All God's angels ... him," comes from one of the books that Moses wrote. The second quotation, "He is the one who makes ... fire," is from the Psalms.
This means Jesus. The author refers to him as the "firstborn" to emphasize the Son's importance and authority over everyone else. It does not imply that there was a time before Jesus existed or that God has other sons like Jesus. AT: "his honored Son, his only Son" (See: [[rc://en/ta/man/translate/figs-metaphor]])