When are the three matters mentioned in the hadith considered to break the prayer?

The questioner : If a woman, a dog, or a donkey passes in front of the one praying, does the prayer become invalid?

The Shaykh : Yes.

The questioner : Now, Shaykh, is there a specified distance involved in this?

The Shaykh : My dear, first, regarding the one who has not placed a barrier (sutrah), the prayer is invalidated by these things. Do you understand this first point? Second, the invalidation of the prayer is conditional on the object passing between him and the place of his prostration, not behind the place of his prostration. So if a person is praying without a barrier and one of these three things passes behind the place of his prostration, it does not break the prayer. And if he has placed a barrier, if one of them passes between him and the barrier, it does not break the prayer.

The questioner : Is the presence of a barrier a condition?

The Shaykh : It is not just like that. We have two scenarios: a man praying facing a barrier and another man not praying facing a barrier. For the first one, it does not harm him if any of these three things passes in front of him, whether the passing is between him and the barrier or behind the barrier. This is clear.

The questioner : Clear, my Shaykh.

The Shaykh : As for the second man, the one who has not placed a barrier, if one of the three things passes between him and the place of his prostration, his prayer becomes invalid. However, if it passes behind the place of his prostration, his prayer is valid.