Komentarz do Samuela II 5:7

And David conquered – When he saw that it was not possible to conquer from the side of the city gate he went to the other side where the stronghold stood and conquered the stronghold of Zion. Therefore it was afterwards called the city of David, because he himself conquered it.

the stronghold of Zion – This is the name of a strong fortress next to Jebus.

“And David conquered the stronghold of Zion which is the city of David. And David said on that day; "Whoever smites the Jebusites and reaches the tzinor…” (Shmuel II 5:7-8) The tzinor is the drainage channel out which the water flows. With the elimination of the tzinor one would also destroy the blind and lame whom David hated because they prevented him from coming into the house. The one who does this will receive some reward which was not made explicit, therefore they said that there were ‘blind and lame’ there while in reality it was this (the tzinor) which prevented David from coming into the house. Perhaps its destruction, aside from removing the covenant which the forefathers made with the Yevusi, is the destruction of the building where these images were. With the destruction of this tzinor these idols would be destroyed. It is possible that one can say in explanation that there was possibly a place that one could not enter without passing before these idols. And these idols were made in such a way that they caused extremely heavy iron rods to swing powerfully across the entrance, therefore no one could pass lest they be struck by the rods. We have heard that such statues have been made in a few places, and such an idea is not so difficult to conceive for one who understands the motions of weights, winds, water and mercury – but this is not the place to explain how such things are possible. They made these idols in the form of the blind and lame because blind and lame people have sticks on which they lean. It appears to me that these idols were next to the drainage channel and they discharged the water out of their mouths. Some of the water would actually enter into them in order to move these sticks. This is why everyone had to beware not to enter there, and that when someone struck the drainage channel in order that water no longer flowed into these idols it would be far easier to destroy them.