An expedition of the Ansar was operating in Persia with their leader. 'Umar used to send expeditions by turns every year, but he neglected them. When the expired, the people of expedition appointed on the frontier came back. He ('Umar) took serious action against them and threatened them, though they were the Companions of the Messenger of Allah ﷺ. They said: 'Umar you neglected us, and abandoned the practice for which the Messenger of Allah ﷺ commanded to send the detachments by turns. (Using translation from Abū Dāʾūd 2960)
أَنَّ جَيْشًا مِنَ الْأَنْصَارِ كَانُوا بِأَرْضِ فَارِسَ مَعَ أَمِيرِهِمْ وَكَانَ عُمَرُ ؓ يُعْقِبُ الْجُيُوشَ فِي كُلِّ عَامٍ فَشُغِلَ عَنْهُمْ عُمَرُ ؓ فَلَمَّا مَرَّ الْأَجَلُ قَفَلَ أَهْلُ ذَلِكَ الثَّغْرِ فَاشْتَدَّ عَلَيْهِ وَأَوْعَدَهُمْ وَهُمْ أَصْحَابُ رَسُولِ اللهِ ﷺ قَالُوا يَا عُمَرُ إِنَّكَ غَفَلْتَ عَنَّا وَتَرَكْتَ فِينَا الَّذِي أَمَرَ بِهِ النَّبِيُّ ﷺ مِنْ إِعْقَابِ بَعْضِ الْغَزِيَّةِ بَعْضًا