The Messenger of Allah ﷺ said, "Show modesty before Allah as He truly deserves."We said, "Messenger of Allah, we do show modesty, praise be to Allah."He replied, "That is not what I mean. True modesty before Allah is that you guard the head and what it contains, the stomach and what it holds, that you remember death and decay, and that whoever desires the Hereafter leaves behind the adornment of this world. Whoever does this has shown true modesty before Allah."
حدثنا يحيى بن موسى حدثنا محمد بن عبيد عن أبان بن إسحق عن الصباح بن محمد عن مرة الهمداني
قال رسول الله ﷺ استحيوا من الله حق الحياء قال قلنا يا رسول الله إنا نستحيي والحمد لله قال ليس ذاك ولكن الاستحياء من الله حق الحياء أن تحفظ الرأس وما وعى والبطن وما حوى ولتذكر الموت والبلى ومن أراد الآخرة ترك زينة الدنيا فمن فعل ذلك فقد استحيا من الله حق الحياء
[Its chain is daif]. Ahmad (1/387) also reported it through Muhammad bin Ubayd, and its chain is daif because of Sabbah bin Muhammad. Nevertheless, Hakim (4/323) graded it sahih, and Dhahabi agreed with him. In the chain of Mustadrak it appears as Sabbah bin Muharib, which is a mistake. The hadith has daif corroborating narrations (which are rejected) in Tabarani's Mujam al-Kabir (3/219, no. 3192, 10/1882, no. 10290), and elsewhere.