Abu Hurairah reported,
The Prophet ﷺ said, "A group will continue to uphold this matter, standing firm upon the truth. Those who oppose them will cause them no harm, until the command of Allah 
comes while they remain in that state."
Ahmad 8930
Sahihحدثنا قتيبة حدثنا ليث عن ابن عجلان عن القعقاع بن حكيم عن أبي صالح
عن أبي هريرة
أن النبي ﷺ قال لن يزال على هذا الأمر عصابة على الحق لا يضرهم خلاف من خالفهم حتى يأتيهم أمر الله عز وجل وهم على ذلك
Its isnad is sahih. It has passed at 8465, and the wordings of this hadith are very numerous, all conveying this same meaning. See what will come at 20802, 20835, 20847, 20909, 20918, 20834, 20803, 20821, 20823, 20824, 20833. The hadith, with all its wordings, is found in Bukhari 9/125, in Muslim in the book of leadership, hadith 170 with its repetitions, in Abu Dawud at the beginning of the book of tribulations, and in Tirmidhi 2192, 2229.