Allah states that Talut, the king of the Children of Israel, marched forth with his soldiers and the Israelites who obeyed him. His army was of eighty thousand then, according to As-Suddi, but Allah knows best. Talut said:
(Verily, Allah will try you) meaning, He will test you with a river, which flowed between Jordan and Palestine, i.e. , the Shari`ah river, according to Ibn `Abbas and others. He continued,
(So whoever drinks thereof, he is not of me;) meaning, shall not accompany me today,
(and whoever tastes it not, he is of me, except him who takes (thereof) in the hollow of his hand.) meaning, there is no harm in this case. Allah then said:
(Yet, they drank thereof, all, except a few of them.)
Ibn Jurayj stated that Ibn `Abbas commented, "Whoever took some of it (the river's water) in the hollow of his hand, quenched his thirst; as for those who drank freely from it, their thirst was not quenched."
Ibn Jarir reported that Al-Bara' bin `Azib said, "We used to say that the Companions of Muhammad who accompanied him on the battle of Badr were more than three hundred and ten, just as many as the soldiers who crossed the river with Talut. Only those who believed crossed the river with him." Al-Bukhari also reported this.
This is why Allah said:
(So when he had crossed it (the river), he and those who believed with him, they said: "We have no power this day against Jalut (Goliath) and his hosts.")
This Ayah indicates that the Israelites (who remained with Saul) thought that they were few in the face of their enemy who were many then. So, their knowledgeable scholars strengthened their resolve by stating that Allah's promise is true and that triumph comes from Allah Alone, not from the large numbers or the adequacy of the supplies. They said to them:
("How often has a small group overcome a mighty host by Allah's leave" And Allah is with As-Sabirin (the patient).)