"In reply to the statement that Christ was the Son of David, Jesus said, “How then doth David in Spirit [the Spirit of Inspiration from God] call Him Lord, saying, The Lord said unto my Lord, Sit Thou on My right hand, till I make Thine enemies Thy footstool? If David then call Him Lord, how is He his son? And no man was able to answer Him a word, neither durst any man from that day forth ask Him any more questions.” DA 609.1"
"He saith unto them, How then doth David in spirit call him Lord, saying,"
The EGW passage is a direct quote from Matthew 22:43.
"The Lord said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool."
The EGW passage is a direct quote from Psalms 110:1.