Water seeping through my foundation in the garage - what is the source?
I would say to wait and see if the water continues to come in after a few days. It is quite possible that the sprinkler water is seeping through above the slab.
Are there bathrooms or other water usage utilities above where the leak is? Pipes usually rise vertically from the ground to the bathroom.
You could also try to shut off the main water valve for as long as possible to see if the water ingres shows down. Switch off water heaters before you do this.
You need to adjust the sprinkler heads so that they are not spraying on the house.