A “Lord” = YHVH. From havah (to be, become) or hayah (to come to pass, become, be). This is the name of the God of Israel, the self-existent and eternal one, the tetragrammaton. This pronunciation has been lost to time so “Lord” is generally used in its place.
B “swore” = shaba. Perhaps from sheba (seven – the number of perfection/sacred fullness). This is to swear, curse, vow, make a covenant. Properly, it can mean to be complete. This is to seven oneself – as in affirming something so strongly it is as though it were said seven times.
C “David” = David. From the same as dod (beloved, love, uncle); the root may mean to boil, which is used figuratively to describe love. So, this implies someone you love such as a friend, a lover, or a close family member like an uncle. David’s name likely means something like “beloved one.”
D “sure” = emet. From aman (to believe, endure, fulfill, confirm, support, be faithful, put one’s trust in, be steadfast. Figuratively, this is to be firm, steadfast, or faithful, trusting, believing, being permanent, morally solid). This is firmness or stability. Figuratively, it is faithfulness, truth, or trustworthiness. This is the same root that “amen” comes from.
E “turn back” = shub. To turn back, return, turn away – literally or figuratively. Doesn’t necessarily imply going back to where you started from. This is also the root verb for the Hebrew word for repentance “teshubah.”