Abdullah ibn Mas’ud reported: The Messenger of Allah, peace and blessings be upon him, said, “Be modest before Allah, as is His right.” We said, “O Messenger of Allah, surely we have modesty, all praise is due to Allah!” The Prophet said, “It is not so. Rather, modesty before Allah, as is His right, is to guard the mind and what runs through it, to guard the stomach and what fills it, and to reflect upon death and trials. Whoever desires the Hereafter, let him abandon the embellishments of worldly life. Whoever does so has been modest before Allah, as is His right.”
Source: Sunan al-Tirmidhī 2458
Grade: Sahih (authentic) according to Al-Suyuti
عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ اسْتَحْيُوا مِنْ اللَّهِ حَقَّ الْحَيَاءِ قَالَ قُلْنَا يَا رَسُولَ اللَّهِ إِنَّا نَسْتَحْيِي وَالْحَمْدُ لِلَّهِ قَالَ لَيْسَ ذَاكَ وَلَكِنَّ الِاسْتِحْيَاءَ مِنْ اللَّهِ حَقَّ الْحَيَاءِ أَنْ تَحْفَظَ الرَّأْسَ وَمَا وَعَى وَالْبَطْنَ وَمَا حَوَى وَلْتَذْكُرْ الْمَوْتَ وَالْبِلَى وَمَنْ أَرَادَ الْآخِرَةَ تَرَكَ زِينَةَ الدُّنْيَا فَمَنْ فَعَلَ ذَلِكَ فَقَدْ اسْتَحْيَا مِنْ اللَّهِ حَقَّ الْحَيَاءِ
2458 سنن الترمذي كتاب صفة القيامة والرقائق والورع باب منه
967 المحدث السيوطي خلاصة حكم المحدث صحيح في الجامع الصغير