King Solomon actually was one of King David's sons.
# has fulfilled it
"has caused it to happen." The word "it" refers to what God had promised. AT: "has ensured that he fulfilled his promises" (See: [[rc://en/ta/man/translate/figs-explicit]])
# with his own hands
The hand is a metonym for power. AT: "by his own power" (See: [[rc://en/ta/man/translate/figs-metonymy]])