רַגְלֵ֤י חסידו [חֲסִידָיו֙] יִשְׁמֹ֔ר וּרְשָׁעִ֖ים בַּחֹ֣שֶׁךְ יִדָּ֑מּוּ כִּֽי־לֹ֥א בְכֹ֖חַ יִגְבַּר־אִֽישׁ׃
Iniingatan Niya ang mga paa ng Kanyang mga tapat, ngunit ang masasama ay pinatatahimik sa kadiliman; sapagkat hindi sa sariling lakas mananaig ang tao.
Rashi
His pious ones. It is spelled חֲסִידוֹ "His pious one" but read חֲסִידָיו "His pious ones," [meaning] whether a single one or many. Similarly "may His adversaries be broken." [The reading is מְרִיבָיו "His adversaries" but] the spelling is מְרִיבוֹ "His adversary," meaning whether a single adversary or many.
Radak
His faithful: It is written without a [letter,] yod, but is read with a yod. And likewise (in I Samuel 2:10), "His enemies, upon him." And the matter is the same, since the yod of the plural sometimes drops out.
Metzudat David
He guards the steps of His faithful: Meaning to say, indeed everything is with justice - for the steps of the righteous are guarded from being caught; but the evildoers are cut off when the darkness of [their] punishments comes, when their measure is full.