What is the meaning of "Shnei Rechev Susim"?
Radak: It is two horses and riders on them.
Five horses remained. Why did they send only two?
Radak: They picked the best two 1 .
Malbim: It sufficed to send two men. There was no need to endanger more than two.
If Aram truly left, they could send weak horses, and the riders can take healthy horses from reach Machaneh Aram. However, if it is an ambush, they need healthy horses to return quickly to the city! (PF)