To add to the previous response you need to also look at what the hole looks like.

If on or near the road side of the tire a pinhole will be a nail, staple, etc. A small slit will be glass. In each case check the tire at that point, both on the inside and outside. It's best on the inside to feel with your fingers, but be careful!

If on the rim side it will generally be either side-by-side slit punctures ("snakebite"), a large roundish puncture or a single curved slit to one side, often with a bubble next to it. the first is a pinch flat - underinflation or too narrow a tire for the rim, resulting in too little rim to pavement distance. The second is a rim tape/spoke hole problem and the third is a spoke poking through. I'm sure it's not an issue in your case but flats can also happen from stress at the valve stem from underinflation and the tube migrating (stretched on one side of stem, folded on the other).

You did not mention a blowout so I assume that is not an issue, but a blowout will be quite a big tear and is ALWAYS either improper mounting, tire bead defect, or serious damage to the tire's casing - never the fault of the tube.