אִם־גָּ֭מַלְתִּי שֽׁוֹלְמִ֥י רָ֑ע וָאֲחַלְּצָ֖ה צוֹרְרִ֣י רֵיקָֽם׃
si j’ai rendu la pareille à qui m’a fait du mal, et dépouillé qui m’a pris en haine sans motif,
Rashi
those who betray [to the extent of] destitution Robbers and impounders, who leave the poor destitute of their property, as (above 7:5): “and I stripped my adversary into emptiness (ריקם).”
Radak
ועבדיך, the letter ו at the beginning of this word substitutes for the word אבל, “but”. In other words: “no my lord, not as you have said; but your servants simply came here to buy food.” The use of the letter ו instead of the word אבל is not unique, as it also occurs in Psalms 7,5 ואחלצה צוררי ריקם, “but I have rescued my foe without reward.”
Chizkuni
לפלא נדר, “in fulfillment of a vow;” there are two diametrically opposite ways of explaining the word לפלא. One is the one we just used, the other we find in a verse in Deuteronomy 17,8: כי יפלא ממך דבר, where it means “if something is concealed from you;” another example where the same expression is used in a similarly contradictory manner is the word דשן, and לדשנו, in Exodus 27,3 which can mean to remove ashes and dross, and which can mean: to saturate, to have a surfeit of, (in the positive sense, such as when applied to a harvest.) Also, in Zachariah 3,4 מחלצות, where it means fancy priestly robes, whereas in Psalms 7,5, ואחלצה צוררי, it means: “I stripped my oppressors, (removed their protective clothing)” The author quotes another example or two of the same phenomenon.