Fiqh-us-Sunnah - 5.119

Hadith 5.119.1

Staying in the Valley of Al-Mohasab

It is established that the Prophet (peace be upon him) on his way from Mina to Makkah rested for a while at Al-Mohasab, where he offered Zuhr, 'Asr, Maghrib and 'Isha prayers. Ibn 'Umar would always do likewise.
There is disagreement among the scholars as to its desirability. 'Aishah said that the Prophet (peace be upon him) rested at Al-Mohasab because it was easier to do so, but it is not a sunnah. Hence, one may or may not do so.
Al-Khattabi said that it was something practiced before but was later on abandoned. Tirmidhi said that some scholars liked to rest at Al-Abtah without treating it as necessary, except those who liked it.
The wisdom of resting at this place is to thank Allah for what He bestowed upon His Prophet (peace be upon him) in the form of victory over his enemies who boycotted Banu Hashim and Banu Al-Mutallib and foreswore that they will neither marry their women nor sell anything to them unless they hand over the Prophet (peace be upon him) to them.
Ibn Al-Qayyim said, "The Prophet (peace be upon him) intended to proclaim the rites of Islam at a place where disbelief, blasphemy, and hostility to Allah and His Messenger were dominant."
This was the usual practice of the Prophet (peace be upon him). He would use every opportunity to proclaim the Oneness of Allah at places once dominated by symbols of disbelief and polytheism. One such example is that the Prophet (peace be upon him) ordered that a Mosque in Ta'if be built in the same place where once idols of Lat and 'Uzza stood.