It was narrated from Ibn ʻUrmar that It was said to `Umar:

Why don`t you appoint a successor? He said: If I do not do that, one who is better than me did not do it either, namely the Messenger of Allah (ﷺ); if I do that, one who is better than me did it too, namely Abu Bakr.

حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ، حَدَّثَنَا هِشَامُ بْنُ عُرْوَةَ، عَنْ أَبِيهِ، عَنِ ابْنِ عُمَرَ، أَنَّ عُمَرَ، قِيلَ لَهُ أَلَا تَسْتَخْلِفُ فَقَالَ إِنْ أَتْرُكْ فَقَدْ تَرَكَ مَنْ هُوَ خَيْرٌ مِنِّي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَإِنْ أَسْتَخْلِفْ فَقَدْ اسْتَخْلَفَ مَنْ هُوَ خَيْرٌ مِنِّي أَبُو بَكْرٍ رَضِيَ اللَّهُ عَنْهُ‏.‏