Good News Translation has dropped the redundant information found in the beginning of this verse in Revised Standard Version. It has already been stated in verse 2 that Rechab and Baanah were the sons of Rimmon and that he was from Beeroth.

Set out: that is, started out on their journey. Some may wish to translate “started going [to Ishbosheth’s house].”

The heat of the day: as seen in 1 Sam 11.11, this expression refers to the time of day when the sun is strongest—at approximately noon. Compare also Gen 18.1.

The Masoretic Text has the name Ish-bosheth in this verse and the name “Mephibosheth” in the previous verse. Though some manuscripts of the Septuagint read “Mephibosheth” in both of these verses, Critique Textuelle de l’Ancien Testament gives an {A} rating to the Masoretic Text here.

His noonday rest: An American Translation has “his mid-day siesta.” In some cultures there is a special term for the rest taken in the middle of the day.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on the First and Second Books of Samuel, Volume 2. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here .