Absalom sent spies throughout all the tribes Before he left Jerusalem he took care to send his emissaries into all parts; doubtless under colour of inviting persons of distinction to the sacrifice; but in reality to carry the watchword and signal, before agreed on between them. As soon as ye shall hear the sound of the trumpet, &c. This was the signal which was to be given for the people's taking up arms, their hearing the sound of the trumpet, which Absalom took care should be blown in all the tribes at the same time, by persons purposely placed in the towns and villages, at such a distance from one another as that each trumpet could be heard by the person appointed to blow the next. The spies, or emissaries, immediately upon hearing the sound of it, were to proclaim that Absalom was crowned king in Hebron. Upon this being done, all his partisans, it is likely, shouted, God save King Absalom.
Related Commentaries of 2 Samuel 15:10
2 Samuel 15:10
10 But Absalom sent spies throughout all the tribes of Israel, saying, As soon as ye hear the sound of the trumpet, then ye shall say, Absalom reigneth in Hebron.