Bukhari

Hadith Commentary:
(1)
It was the practice of the Messenger of Allah sallallahu alayhi wa sallam every night that whenever he would retire to his bed at night, he would bring both hands together, blow into them, recite: ﴿Qul huwa Allahu ahad, Qul a‘udhu bi-Rabbil-falaq, and Qul a‘udhu bi-Rabbin-nas﴾, and then, as much as possible, pass his hands over the front part of his entire body, starting from there. The Prophet sallallahu alayhi wa sallam would perform this action three times. (Sahih al-Bukhari, Fada’il al-Qur’an, Hadith: 5017) However, when he was unwell, he would pay special attention to this practice. When the pain increased during his final illness, Aisha radi Allahu anha would perform this action for him. (Sahih al-Bukhari, al-Maghazi, Hadith: 4439)
(2)
The mention of reciting Ayat al-Kursi at bedtime is also found in the hadiths. (Sahih al-Bukhari, Fada’il al-Qur’an, Hadith: 5010) Similarly, the Messenger of Allah sallallahu alayhi wa sallam advised Abdullah ibn Mas‘ud radi Allahu anhu to recite the last two verses of Surah al-Baqarah at night. (Sahih al-Bukhari, Fada’il al-Qur’an, Hadith: 5009)
(3)
Some individuals are of the opinion that ruqyah (incantation) and seeking refuge (ta‘awwudh) are only permissible in the case of illness, and not in normal circumstances; this hadith refutes the view of such individuals. (Fath al-Bari: 11/151)

Benefits and Issues:
➊
In one narration, these words are mentioned: The Prophet sallallahu alayhi wa sallam would join both his palms together and recite: “Qul Huwa Allahu Ahad, Qul A’udhu bi-Rabbil-Falaq, Qul A’udhu bi-Rabbin-Nas” (all three surahs). Then he would blow into them and wipe both hands over his body as far as possible, and he would do this over his head, face, and the front part of his body. He would do this three times in the same manner. (See: Sahih al-Bukhari, Virtues of the Qur’an, Chapter: The Virtue of the Mu’awwidhat, Hadith: 5017)

➌
At the time of sleeping, one should recite these surahs in this manner so that the reward of acting upon the Sunnah is also attained, and Allah’s protection is also granted.