"And Moses and Aaron gathered the assembly together, etc." From here we learn that the small holds the much. Come and see: the face of the rock was only small, yet the whole assembly of Israel stood upon the face of the rock.
"Hear now, you rebels (ha-morim)." For so they call a fool in the coastal cities — morah — and it is in the Greek tongue.
"Shall we bring forth water for you from this rock (ha-min ha-sela ha-zeh)?" He did not know which rock it was, because at the time when the well departed, the rock had gone and seated itself among the other rocks. Moses took the staff and touched a rock and said, "What do you suppose — shall we bring forth water for you from this rock?" And they supposed he was telling them that that rock would bring forth water for them, but he did not say it with that intent, because he did not recognize it. As soon as he laid the staff upon the rock, the rock began to drip, because of the Name that was engraved upon the staff. When Moses saw that it dripped, Moses thought that it needed a blow with the staff, as it had been at first, as it is said, "and you shall strike the rock, and water shall come out of it, etc." (Exodus 17:6). At once Moses raised his hand and struck the rock with the staff twice.
And why was it necessary to strike it twice? Because the first time it brought forth blood, and because it did not do the bidding of the Omnipresent, he struck it a second time, so that it would bring forth water; and on account of Moses' honor it brought forth water. And whence do we know that the first time it brought forth blood? As it is said, "Behold, He struck the rock, and waters gushed out (va-yazuvu), etc." (Psalms 78:20) — and "va-yazuvu" means nothing but blood, as it is said, "And if a woman has a flow (yazuv) of her blood, etc." (Leviticus 15:25). And whence do we know that the blood turned into water? As it is said, "Who turned the rock into a pool of water" (Psalms 114:8). At the first blow it brought forth blood, just as Moses our teacher, peace be upon him, struck the Nile in Egypt, and the waters too turned to blood. At the second blow the Holy One, blessed be He, turned the blood before them, and many of the Israelites who quarreled with Moses went out and were swept away, as it is said, "and streams overflowed (u-nechalim yishtofu)" (Psalms 78:20).