Caleb hushed the people before Moses and said, “Let us by all means go up, and we shall gain possession of it, for we shall surely overcome it.”

ויהס כלב את העם, he silenced the people who had begun to raise their voices, as they did afterwards when the Torah reports in 14,1 “all the people raised their voices and the cried the whole night.”

אל משה, so that Moses would have a chance to reply. Perhaps Moses replied with the words he referred to in Deuteronomy 1,29: “I told you not to be scared and not to be afraid of the inhabitants of that land, etc.”

Calev reinforced Moses’ words by saying: עלה נעלה, it is appropriate for us to ascend for they will not be able to stand up against us to prevent us from progressing;

ויהס כלב את העם, Caleb silenced the people, etc. Seeing that an ordinary individual is not capable of silencing a people numbering hundreds of thousands, the Torah adds the words אל משה, to tell us that he silenced them in order to make them listen to Moses, not to himself. We know from Deut. 33,5 that Moses' rank was equivalent to the rank of a king. Caleb invoked the awe and respect due to a king in order to silence the people. Having invoked Moses' authority, he said: "we most certainly are able to to go up and take possession of the land." He meant that in spite of the other spies' having said: "we cannot overcome this people," he felt that the Israelites would be able to prevail.

ויהס, he silenced them by using his psychological insights.

The verse states: “And Caleb stilled [vayyahas] the people toward Moses” (Numbers 13:30). Rabba says: This means that he persuaded them [hesitan] with his words. Vayyahas and hesitan share the same root in Hebrew.

Caleb said to himself: If I speak they will also say something about me and stop me from speaking. He began to speak and said to them: And is this the only thing that the son of Amram, Moses, has done to us? They thought that he wanted to relate something to the discredit of Moses, and they were silent.

He then said to them: He took us out of Egypt, and split the sea for us, and fed us the manna. If he says to us: Build ladders and climb to the heavens, should we not listen to him? “We should go up at once,” even to the heavens, “and possess it” (Numbers 13:30).