Hadith: Two eyes will not be touched by the Fire: an eye which has wept out of fear of Allah, and an eye which has spent the night guarding in the cause of Allah

عن ابن عباس رضي الله عنهما مرفوعاً: «عَيْنَانِ لاَ تَمسُّهُمَا النَّار: عَيْنٌ بَكَتْ من خَشْيَة الله، وعَيْنٌ بَاتَت تَحْرُسُ في سَبِيل الله».
[صحيح] - [رواه الترمذي]

Ibn ‘Abbās (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Two eyes will not be touched by the Fire: an eye which has wept out of fear of Allah, and an eye which has spent the night guarding in the cause of Allah."
[Authentic hadith] - [Narrated by At-Termedhy]

Explanation

The Fire of Hell will not touch an eye that cried out of fear of Allah, the Almighty. When a person remembers the greatness of Allah, His power over His servants, and, at the same time, he recalls his own state and his negligence in fulfilling the rights of Allah upon him, he weeps in hope of receiving Allah's mercy and in fear of His wrath and punishment. Such a person is promised to be saved from the Fire. Another eye that the Fire will not touch is an eye that stayed up at night guarding in the cause of Allah in battlefields and on Muslim frontiers to protect the lives of Muslims. The statement: "Two eyes will not be touched by the Fire," is a figure of speech whereby a part of something is mentioned with the intention of referring to the whole. Thus, the intended meaning is that the person who weeps out of fear of Allah, as well as he who spends the night guarding in the cause of Allah, Allah will make their whole bodies (not just the eyes) forbidden to the Fire.