Abu Muhammad claimed that the witr prayer is obligatory. Ubada bin Samit responded, "Abu Muhammad has spoken falsely. I bear witness that I heard the Messenger of Allah ﷺ say, 'There are five prayers which Allah has made obligatory upon His servants. Whoever performs their ablution well, prays them at their proper times, and completes their bowing, prostration, and humility, has a covenant with Allah that He will forgive him. But whoever does not do so has no covenant with Allah. If He wishes, He may forgive him, and if He wishes, He may punish him.'"
حدثنا حسين بن محمد حدثنا محمد بن مطرف عن زيد بن أسلم عن عطاء بن يسار
زعم أبو محمد أن الوتر واجب فقال عبادة بن الصامت كذب أبو محمد أشهد سمعت رسول الله ﷺ يقول خمس صلوات افترضهن الله على عباده من أحسن وضوءهن وصلاتهن لوقتهن فأتم ركوعهن وسجودهن وخشوعهن كان له عند الله عهد أن يغفر له ومن لم يفعل فليس له عند الله عهد إن شاء غفر له وإن شاء عذبه
Its isnad is sahih. Abdullah Sanabihi's identity is disputed. Some say he is Abdul-Rahman bin Usayla, one of the trustworthy senior successors, whose kunya was Abu Abdullah, meaning that the narrators dropped "Abd." Others say he was rather a companion from Madinah. The hadith has already appeared at 22592.