Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: "If one of you is able to stop anyone from passing in front of him, let him do so, for the reward of the one who passes in front of a person praying is less than that of the one in front of whom he passes."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9256