Radak

He is crushed, he humbleth himself: – ודכה, the Kethib is written with waw, and the Keri (ידכה) with yodh, and the waw and the yodh interchange. He says: that in yet another sense it is the way of the wicked to get the poor into his power. He makes himself (as one) crushed and humble. He and his band pretend that they are weak and crushed, so that the children of men may not be on their guard against them, but go forth with them in the company on the way; and then when they are far from any human habitation they reveal their strength and power and seize them; and this (is the meaning of) And the hapless fall by their strong (ones): – (The Kethib) is written as one word, חלכאים, but the Keri reads as two words, כאים חל; and its interpretation is: “the congregation of the stricken and the weary.” And עצומיו (their strong ones) is an adjective for “their strong limbs” – their hands and feet. And all these are the ways which he narrates in the matter of the wicked, to shew that in all these ways he may be wary of the sons of men, but cannot be wary of God, and (that) he shews himself to be no fearer of God; for he says in his heart that He (God) does not see and does not know, as he says: