And he shall be like a tree planted by the rivers of water. The comparison of a man to a. tree is frequent in the Book of Job (Job 8:16, Job 8:17; Job 14:7-10; Job 15:32, Job 15:33, etc.), and occurs once in the Pentateuch (Numbers 24:6).
We find it again in Psalms 92:12-14, and frequently in the prophets. The "rivers of water" spoken of ( פַּלְגַ־מָיִם) are undoubtedly the "streams" (Revised Version) or "canals of irrigation" so common both in Egypt and in Babylonia, by which fruit trees were planted, as especially date-palms, which need the vicinity of water.
That such planting of trees by the waterside was known to the Israelites is evident, both from this passage and from several others, as Numbers 24:6; Ecclesiastes 2:5; Jeremiah 17:8; Ezekiel 17:5, Ezekiel 17:8, etc.
It is misplaced ingenuity to attempt to decide what particular tree the writer had in his mind, whether the palm, or the oleander, or any other, since he may not have been thinking of any particular tree.
That bringeth forth his fruit in his season. Therefore not the oleander, which has no fruit, and is never planted in the East, but grows naturally along the courses of streams. His leaf also shall not wither.
Compare the contrary threat of Isaiah against the wicked of his time, "Ye shall be as an oak whose leaf fadeth, and as a garden that hath no water" (Isaiah 1:30). And whatsoever he doeth shall prosper; rather, perhaps, in whatsoever he doeth he shall prosper.