What is "Korei Dagar"?
Rashi: A cuckoo bird chirps.
Why does it say "v'Lo Yalad"?
Rashi: This bird gathers chicks that it did not give birth to them. When they mature, they will not follow it, for they are not its species. So one who amasses wealth against Torah law (will lose it).
Radak, Malbim citing Targum Yonasan: It sits on eggs of another bird, and warms them until they hatch. The chicks are not its species, so they will abandon it and not follow it 1 . Radak - if you see a Rasha prosper financially, do not be astounded why Hashem did not give to him like his ways. He will lose his wealth, or he will die and his wealth will pass to others. He will not complete his days with his wealth.
Malbim: This hints to the second condition for trust (to merit success). His actions cannot contradict his trust. If one says that he trusts in Hashem, but he strives to gather wealth through blood and cheating, clearly his trust is not complete, therefore he will not keep his wealth. This is like the nature that Hashem put in the cuckoo.
What is the meaning of "Yihyeh Naval"?
Rashi citing Targum Yonasan: He will be called a Rasha.
Radak: He will die before his time, if he does not lose his wealth in the middle of his life, and be base and lowly in his end.
Malbim: He will be worse than one who never had wealth. He will keep his nature to steal, extort and do despicable acts.
Why is "Yamav" written without a Yud after the Mem to indicate the plural?
Radak: We find like this - "Yechatu Merivav Alav ba'Shamayim Yar'em" (Shmuel I, 2:10. Merivav and Alav are written without a Yud before the Vov.)
