The shady trees
tse'el (tseh'-el)
the lotus tree -- shady tree.
cover
cakak (saw-kak')
to entwine as a screen; by implication, to fence in, cover over, (figuratively) protect -- cover, defence, defend, hedge in, join together, set, shut up.
him with their shadow
tselel (tsay'-lel)
shade -- shadow.
the willows
`arab (aw-rawb')
a willow (from the use of osiers as wattles) -- willow.
of the brook
nachal (nakh'-al)
a stream, especially a winter torrent; (by implication) a (narrow) valley (in which a brook runs); also a shaft (of a mine) -- brook, flood, river, stream, valley.
compass him about
cabab (saw-bab')
to revolve, surround, or border; used in various applications, literally and figuratively (as follows)