On that day he said, “Whoever attacks the Jebusites must use the water shaft to reach the lame and blind who are despised by David.” That is why it is said, “The blind and the lame will never enter the palace.”
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 5:8 >And David said on that day: 'Whosoever smiteth the Jebusites, and getteth up to the gutter, and taketh away the lame and the blind, that are hated of David's soul — .' Wherefore they say: 'There are the blind and the lame; he cannot come into the house.'