John Calvin Commentary Genesis 26:32

"And it came to pass the same day, that Isaac`s servants came, and told him concerning the well which they had digged, and said unto him, We have found water." — Genesis 26:32 (ASV)

And it came to pass the same day. Therefore, it appears (as I have said a little before) that the waters were not found instantly. If it is asked from where a supply of water had been obtained for his cattle and his household during the intervening days, I have no doubt, indeed, that he either bought it or was compelled to go to a distance to see if anyone could be found from whom he might obtain it by request.

With respect to the name (Sheba), they are mistaken, in my judgment, who consider it to be any other than that which Abraham had first given to the well. For since the Hebrew word is ambiguous, Abraham alluded to the covenant which he had made with the king of Gerar; but now Isaac, recalling this ancient memorial, connects it with the covenant in which he himself had engaged.