On the authority of his father, who said: The Messenger of Allah, peace and blessings be upon him, said: "When one of you urinates, let him not touch his penis with his right hand, and when he goes to the privy, let him not wipe himself with his right hand, and when he drinks, let him not drink in a single breath."(1)

32 — Muhammad ibn Adam ibn Sulayman al-Missisi narrated to us, Ibn Abi Za'idah narrated to us, he said: Abu Ayyub — meaning al-Ifriqi — narrated to me, on the authority of 'Asim, on the authority of al-Musayyab ibn Rafi' and Ma'bad, that Harithah ibn Wahb al-Khuza'i said:

Hafsah, the wife of the Prophet, peace and blessings be upon him, narrated to me: that the Prophet, peace and blessings be upon him, used to designate his right hand for his food, his drink, and his garments, and he used to designate his left hand for what was other than that.(2)

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(1) Its chain of transmission is authentic. Aban: he is ibn Yazid al-'Attar, and Yahya: he is ibn Abi Kathir.
It was also recorded by al-Bukhari (153), Muslim (267), al-Tirmidhi (15), al-Nasa'i in "al-Kubra" (28), (29), and (41), and Ibn Majah (310) via multiple paths from Yahya ibn Abi Kathir, with this chain. Some of them restrict it to part of it.
It is found in "Musnad Ahmad" (19419) and "Sahih Ibn Hibban" (1434).
Ibn al-'Arabi said in "'Aridat al-Ahwadhi": Ghufran: a verbal noun like al-ghufr and al-maghfirah, and likewise subhanak; it is in the accusative due to an implied verb, the estimation here being: I seek Your forgiveness. Regarding the seeking of forgiveness here, there are two possibilities: the first: that he asked forgiveness for his omission of the remembrance of Allah in that matter in that state; the second, which is more well-known: that the Prophet, peace and blessings be upon him, asked forgiveness for the inability to give thanks for the blessing in facilitating nourishment, preserving its benefit, and expelling its waste with ease, so that fulfilling its due is accomplished through forgiveness.
(2) Authentic due to corroborating evidence, but this chain is weak due to the weakness of Abu Ayyub al-Ifriqi — who is 'Abdullah ibn 'Ali al-Azraq — and due to the inconsistency of 'Asim — who is ibn Abi al-Nujud — in it. Ibn Abi Za'idah: he is Yahya ibn Zakariyya, and Ma'bad: he is ibn Khalid al-Kufi.
It was also recorded by Abu Ya'la (7042) and (7060), Ibn Hibban (5227), al-Tabarani in "al-Kabir" 23/(346), al-Hakim 4/109, and al-Bayhaqi 1/113 via the path of Ibn Abi Za'idah, with this chain. The narration of those other than Abu Ya'la and al-Bayhaqi is from al-Musayyab alone; they did not pair him with Ma'bad.