2 Samuel 5:8

And David ^{H1732} said ^{H559} on that day ^{H3117}, Whosoever getteth up ^{H5060} to the gutter ^{H6794}, and smiteth ^{H5221} the Jebusites ^{H2983}, and the lame ^{H6455} and the blind ^{H5787}, that are hated ^{H8130} of David's ^{H1732} soul ^{H5315}, he shall be chief and captain. Wherefore they said ^{H559}, The blind ^{H5787} and the lame ^{H6455} shall not come ^{H935} into the house ^{H1004}.

What David said on that day was, "In order to attack the Y'vusi, you have to climb up [from the spring outside the city] through the water tunnel. Then you can do away with those [so-called] 'lame and blind'" (whom David despises - hence the expression, "The 'blind and lame' keep him from entering the house").

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.”

And David said on that day, Whosoever smiteth the Jebusites, let him get up to the watercourse, and smite 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.