AbuSa'eed narrated that the Messenger of Allah (ﷺ) said:
"TheSirat will be placed across Hell, on thorns like the thorns of Sa'danplant.* Then the people will cross it. Some will pass over safe andsound, some will be detained, and some will fall in headfirst." (RU)
English reference (RU): Vol. 5, Book 37, Hadith 4280 (RU)
Arabic reference (RU): Book 37, Hadith 4421 (RU)