Staying at Al-Mahassab is not one of the ceremonies (of Hajj), but Al-Mahassab is a place where Messenger of Allah ﷺ camped (during his Hajjat-al-Wida).  

عَنِ ابْنِ عَبَّاسٍ ؓ لَيْسَ التَّحْصِيبُ بِشَىْءٍ إِنَّمَا هُوَ مَنْزِلٌ نَزَلَهُ رَسُولُ اللَّهِ ﷺ  

Halt at Muhassab is not something (significant from the point of view of the Shari'ah). It is a place of halt where Messenger of Allah (way peace be upon him) halted.  

لَيْسَ التَّحْصِيبُ بِشَىْءٍ إِنَّمَا هُوَ مَنْزِلٌ نَزَلَهُ رَسُولُ اللَّهِ ﷺ  

"At-Tahsib is nothing, it is only a place that the Messenger of Allah camped at."  

لَيْسَ التَّحْصِيبُ بِشَيْءٍ إِنَّمَا هُوَ مَنْزِلٌ نَزَلَهُ رَسُولُ اللَّهِ ﷺ  

"At-Tahsib is nothing, it is only a place that the Messenger of Allah camped at." (Using translation from Tirmidhī 922)  

لَيْسَ الْمُحَصَّبُ بِشَيْءٍ إِنَّمَا هُوَ مَنْزِلٌ نَزَلَهُ رَسُولُ اللهِ ﷺ  

“Staying in Abtah is not Sunnah; the Messenger of Allah ﷺ only stayed there because it was more convenient for his departure.” (Using translation from Ibn Mājah 3067)   

لَيْسَ نُزُولُ الْمُحَصَّبِ بِالسُّنَّةِ إِنَّمَا نَزَلَهُ رَسُولُ اللهِ ﷺ لِيَكُونَ أَسْمَحَ لِخُرُوجِهِ  

Halt at Muhassab is not something (significant from the point of view of the Shari'ah). It is a place of halt where Messenger of Allah (way peace be upon him) halted. (Using translation from Muslim 1312)   

«إِنَّ الْمُحَصَّبُ لَيْسَ بِشَيْءٍ إِنَّمَا هُوَ مَنْزِلٌ نَزَلَهُ رَسُولُ اللهِ ﷺ»