Adam Clarke's Bible Commentary Verse 4. Sharp arrows ] The Chaldee has, "The strong, sharp arrows are like lightning from above, with coals of juniper kindled in hell beneath." On the juniper, see the note on Job xxx. 4, where this passage is explained.
Fiery arrows, or arrows wrapped about with inflamed combustibles, were formerly used in sieges to set the places on fire. See my notes on Eph. vi. 16.
Matthew Henry Commentary
Verses 1-4 - The psalmist was brought into great distress by a deceitful tongue. Ma every good man be delivered from lying lips. They forged false charge against him. In this distress, he sought God by fervent prayer. God can bridle their tongues. He obtained a gracious answer to this prayer Surely sinners durst not act as they do, if they knew, and would be persuaded to think, what will be in the end thereof. The terrors of the Lord are his arrows; and his wrath is compared to burning coals of juniper, which have a fierce heat, and keep fire very long. This is the portion of the false tongue; for all that love and make a lie, shal have their portion in the lake that burns eternally.
Original Hebrew חצי2671 גבור1368 שׁנונים8150 עם5973 גחלי1513 רתמים׃7574