Hadith Q815
إِذَا كَانَ الْمُصَلِّي يُصَلِّي إِلَى سُتْرَةٍ، وَإِبَاحَةِ الْمُرُورِ بَيْنَ يَدَيِ الْمُصَلِّي إِذَا صَلَّى إِلَى غَيْرِ سُتْرَةٍ
That is when the person praying is performing the prayer with a sutrah placed. And when the person praying is performing the prayer without a sutrah, then it is permissible to pass in front of the person praying.
Hadith 815
Sayyiduna Mutlib bin Abi Wada'ah (may Allah be pleased with him) narrates that I saw the Messenger of Allah (peace and blessings be upon him) when he finished his Tawaf, he came to the edge of the Mataf and offered two rak'ahs of prayer, while there was no one between him and those performing Tawaf.