Sahih Muslim 2963 a
Abu Huraira reported that Allah's Messenger (ﷺ) said:
When one of you looks at one who stands at a higher level than you in regard to wealth and physical structure he should also see one who stands at a lower level than you in regard to these things (in which he stands) at a higher level (as compared to him).
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، وَقُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ قُتَيْبَةُ حَدَّثَنَا وَقَالَ، يَحْيَى أَخْبَرَنَا 
 الْمُغِيرَةُ بْنُ عَبْدِ الرَّحْمَنِ الْحِزَامِيُّ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ
 اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ إِذَا نَظَرَ أَحَدُكُمْ إِلَى مَنْ فُضِّلَ عَلَيْهِ فِي الْمَالِ وَالْخَلْقِ فَلْيَنْظُرْ
 إِلَى مَنْ هُوَ أَسْفَلَ مِنْهُ مِمَّنْ فُضِّلَ عَلَيْهِ ‏"‏ ‏.‏