The gates
sha`ar (shah'-ar)
an opening, i.e. door or gate -- city, door, gate, port (-er).
of the rivers
nahar (naw-hawr')
a stream (including the sea; expec. the Nile, Euphrates, etc.); figuratively, prosperity -- flood, river.
shall be opened
pathach (paw-thakh')
to open wide; specifically, to loosen, begin, plough, carve
and the palace
heykal (hay-kawl')
a large public building, such as a palace or temple -- palace, temple.
shall be dissolved
muwg (moog)
to melt, i.e. literally (to soften, flow down, disappear), or figuratively (to fear, faint) -- consume, dissolve, (be) faint(-hearted), melt (away), make soft.