Abd ur-Rahman bin Bishr al-Abdī narrated to me, he said, I heard Muhammad bin Abd Allah bin Ubayd bin Umayr al-Laythī was mentioned near Yahyā bin Sa’īd al-Qattān, so he weakened him severely. Then it was said to Yahyā:
‘More weak than Ya’qūb bin Atā ’?’ He said: ‘Yes’. Then he said: ‘I did not see anyone transmitting on authority of Muhammad bin Abd Allah bin Ubayd bin Umayr’.

وَحَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ بِشْرٍ الْعَبْدِيُّ، قَالَ سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ الْقَطَّانَ، ذُكِرَ عِنْدَهُ مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عُبَيْدِ بْنِ عُمَيْرٍ اللَّيْثِيُّ فَضَعَّفَهُ جِدًّا . فَقِيلَ لِيَحْيَى أَضْعَفُ مِنْ يَعْقُوبَ بْنِ عَطَاءٍ قَالَ نَعَمْ . ثُمَّ قَالَ مَا كُنْتُ أُرَى أَنَّ أَحَدًا يَرْوِي عَنْ مُحَمَّدِ بْنِ عَبْدِ اللَّهِ بْنِ عُبَيْدِ بْنِ عُمَيْرٍ .