Parashas Eikev · Passuk 8:15
who led you through the great and terrible wilderness with its seraphdseraph See note at Num. 21.6. serpents and scorpions, a parched land with no water in it, who brought forth water for you from the flinty rock;
Torah Temimah points to Berachos 38a.
TT lemma: המוציא לך מים.
English: Our Rabbis taught: Over bread one says “ha-motzi lechem min ha-aretz,” because ha-motzi implies “who has brought forth,” as it is written, “who brought forth water for you from the rock of flint.”
Custom (wording of ha-motzi)
The form ha-motzi (past) is grounded in this verse’s language of already having brought forth water from the rock.