"authentic." al-Dhahabī agreed with him, and al-Ḥāfiẓ attributed it (7/489) to Ibn Khuzaymah as well and confirmed it.

"He would prostrate on the buttocks of the palm." It was recorded by Ibn Khuzaymah in his "Ṣaḥīḥ" (1/323/639) and from his route by Ibn Ḥibbān (490 - Mawārid), al-Ḥākim (1/227), and from him al-Bayhaqī (2/107) and Aḥmad (4/295) through various routes from al-Ḥusayn ibn Wāqid: Abū Isḥāq narrated to me, he said: I heard al-Barāʾ ibn ʿĀzib say: and he mentioned it as marfūʿ. al-Ḥākim said: "authentic according to their criteria"! al-Dhahabī agreed with him! Thus they said, and al-Ḥusayn ibn Wāqid was only recorded by al-Bukhārī in a suspended form, so it is according to Muslim's criteria alone, and Abū Isḥāq is ʿAmr ibn ʿAbd Allāh al-Sabīʿī, and there is concern regarding him—despite his reliability—due to his tadlīs and confusion. As for his tadlīs, we are assured by his explicit statement of hearing. As for the confusion, I do not know if al-Ḥusayn heard from him before the confusion or not, except that al-Bayhaqī narrated with his chain from a group who said: Shuʿbah narrated to us, he said: Abū Isḥāq informed me from al-Barāʾ, he said: "When one of you prostrates, let him prostrate on the buttocks of the palm." Ibn Abī Shaybah said in "al-Muṣannaf" (1/261): Wakīʿ narrated to us from Shuʿbah with it. Shuʿbah heard from Abū Isḥāq before the confusion, so the isnād is authentic, and all praise is due to Allāh. It is not said: this is mawqūf, because we say: it is in the ruling of marfūʿ, because such matters are not said based on opinion like other postures of prayer, for they are pure acts of worship, especially since it has been authentically reported from the Prophet (ṣallá Allāhu ʿalayhi wa-sallam) the command to place the palms in prostration and to lean on them, as is extracted in "Ṣifah..