It would be from this side that there would appear the height of unbelief, viz. where appear the horns of Satan, i.e. the east. (Using translation from Muslim 2905d)
خَرَجَ رَسُولُ اللهِ ﷺ مِنْ بَيْتِ عَائِشَةَ فَقَالَ رَأْسُ الْكُفْرِ مِنْ هَاهُنَا مِنْ حَيْثُ يَطْلُعُ قَرْنُ الشَّيْطَانِ