The Messenger of Allah (ﷺ) was asked about sutra of a worshipper; he said: Equal to the back of the saddle.
Sahih Muslim Book 4, Hadith 275
← Previous Hadith We used to say prayer and the animals moved in front of us. We mentioned it to the Messenger of Allah (ﷺ) and he said: If anything equal to the back of a saddle is in front of you, then what walks in front, no harm would come to him. Ibn Numair said: No harm would come whosoever walks in front.

Sahih Muslim Book 4, Hadith 274 Next Hadith → The Messenger of Allah (ﷺ) was asked in the expedition of Tabuk about the sutra the worshipper; he said: Like the back of the saddle.

Sahih Muslim Book 4, Hadith 276