Rashi #1: Misnakesh applies to one who toils and pursues a matter - "v'Archubate Da l'Da Nakshan" (Daniel 5:6), "Pen Tinakesh Achareihem" (Devarim 12:30). Also here, the creditor whom Esav owes (Yakov) will pursue [Esav's] work (earnings, for they belong to him) - "v'Rav Ya'avod Tza'ir" (Bereishis 25:23).

Rashi #2: The creditor (Yakov, whom Esav owes - "v'Rav Ya'avod Tza'ir") will touch and approach all that [the debtor] has. A creditor is entitled to collect from everything!

Radak: The lender will annihilate all that [the borrower] has. He will take his wives and property and loot all that he has. Yenakesh is to snare; Nakesh and va'Yikash are the same matter. The same applies to "va'Yinakshu Mevakshei Nafshi" (38:13).

Malbim: His sons will not find anyone to help them, for the creditor will set traps for all that he has to seize him, to the point that stranger will despoil his earnings, and he will not leave anything to bequeath to his sons.