למה רגשו - הנכון בעיני: כי זה המזמור חברו אחד מהמשוררים על דוד ביום המשחו, על כן כתוב: אני היום ילדתיך, או על המשיח. Why do nations assemble (לָ֭מָּה רָגְשׁ֣וּ - lamah ragshu): What seems correct in my eyes is that this psalm was composed by one of the poets concerning David on the day he was anointed. Therefore, it is written [later in verse 7], "This day I have begotten you." Or [alternatively, the psalm is] about the Messiah.
ורגשו - כמו חברו וכמוהו מרגשת פועלי און. And ragshu [translated here as "assemble," but can also mean rage/tumult] is like "joined together" (chavru). Similar to it is [the phrase in (Psalm 64:3)] "from the assembly/tumult (mirgeshet) of the workers of iniquity."
ולמ"ד לאמים – שורש כמו: ולאם מלאם יאמץ. And the Lamed [prefix] of le'umim (לְאֻמִּ֗ים - peoples): [This Lamed is part of the] root [of the word], as the singular form is le'om (people/nation). As in (Genesis 25:23): "and one people (u-le'om) shall be stronger than the other people (mi-le'om)."
יהגו ריק - בדיבור כמו: ולשוני אם יהגה רמיה והדבור ננתקה את מוסרותימו. Plot/utter vain things (יֶהְגּוּ־רִֽיק - yehgu rik): [This refers to plotting] through speech (be-dibur). Similar [usage of hagah for speech is found], as in [verses like (Psalm 35:28)] "And my tongue shall speak (tehgeh) Your righteousness." And the [specific vain] speech [they utter] is [revealed in verse 3]: "Let us break their bonds asunder."