Muwatta Malik 301
موطأ مالك#301SahihYahya related to me from Malik that Nafi said, "I stood behind Abdullah ibn Umar in one of the prayers when there was no one else with him, and he reached behind with his hand and placed me beside him
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Salim al-HilaliMauquf Sahih
In-book reference: 8:15