Why did they say "ha'Yom"?
Malbim: Call them and answer them today 1 [that the king is the servant of the nation - refer to 12:7:2:2], as if it is a simple matter. Then, they will make you king without conditions.Do not request three days before answering them!
Verse 5 said that the nation already left! Since they would return in three days, presumably most of them were staying in the city, and he could call to them and address them the same day. (PF)
Did they suggest that he be a slave to the nation?!
Radak: Be submissive to them and answer them like they want.
Malbim: If you refuse their request, they will rebel and declare to be king whomever they want. If you begin to compromise with them about the limits of your power and taxes and work [you may demand of them], they will request many things and bind you with an oath and fixed laws that you cannot annul. Rather, promise them more than they request - that they are not servants of the king, rather, the king is their servant, and he must do their will. Make their request like a small matter that intellect obligates. You will gain from this - (a) They will not request more, since you gave to them more than they requested. (b) If you make their request a small matter, they will not put an oath on you and fix laws about this. After you are king, you can rule as you wish; they cannot rebel, for they will fear you!
What is the meaning of "va'Anisam v'Dibarta Aleihem Devarim Tovim"?
Radak citing Targum Yonasan: Answer them nice words and speak proper matters.
Malbim: It explains in Divrei ha'Yamim II, 10:7 "Im Tihyeh l'Tov leha'Am ha'Zeh u'Rtzisem" - you seek only their benefit and will; your will is Batel to theirs.
Will they always be his servants?
Malbim: He will have an unlimited kingship.
