The correct proceedure for diluting concentrated strong acids (or bases) is

Question

to slowly add acid (or base) to water.

to quickly add water to the acid (or base).

to evaporate the water from the acid (or base) in a fume hood.

to add the strong acid to the base until it is neutralized.

Answer 1

to slowly add acid (or base) to water.

If you do it the other way, the reaction is remarkably vigorous and is likely to spit acid all over the place.

Answer 2

...to slowly add acid (or base) to water.