What is the ruling on children under five years old passing in front of a worshipper and playing with the prayer rug?

The passage of a young child in front of a worshipper does not invalidate the prayer. However, it is prescribed for the worshipper to gently prevent them, based on the action of the Prophet, peace and blessings be upon him, with Abdullah or Umar and Zaynab. Umm Salamah narrated: “The Prophet, peace and blessings be upon him, was praying in Umm Salamah’s chamber. Abdullah — or Umar — passed in front of him, and he gestured with his hand like this, so he returned. Then Umm Salamah’s daughter passed by, and he gestured with his hand like this, but she continued. When the Messenger of Allah, peace and blessings be upon him, finished his prayer, he said: ‘They are more assertive.’” It is recommended to repel anything that passes in front of the worshipper, whether human or animal.