1 Samuel 20:18

18 Then Jonathan said to him, "Tomorrow is the New Moon;^[a] you'll be missed because your seat will be empty.

1 Samuel 20:18 Meaning and Commentary

1 Samuel 20:18

Then Jonathan said to David, tomorrow [is] the new moon
The first day of the month, as David had before observed, ( 1 Samuel 20:5 ) ;

and thou shalt be missed, because thy seat will be empty;
or be inquired after, because not in his usual place at mealtime.

Taken from John Gill's Exposition of the Bible

16 Then Jonathan made a covenant with the house of David, saying, "May the Lord hold David's enemies accountable."

17 Jonathan once again swore to David in his love for him, because he loved him as he loved himself.

18 Then Jonathan said to him, "Tomorrow is the New Moon; you'll be missed because your seat will be empty.

19 The following day hurry down and go to the place where you hid on the day this incident began and stay beside the rock Ezel.

20 I will shoot three arrows beside it as if I'm aiming at a target.