Ibn Majah

Benefits and Issues:
➊ Saying «بسم الله» at the beginning of ablution (wudu) is obligatory, because the Messenger of Allah sallallahu alayhi wa sallam said to the noble Companions radi Allahu anhum: “Perform ablution while saying «بسم الله».” [سنن النسائي، الطهارة، حديث : 78]
From this hadith, it is understood that beginning ablution with words other than «بسم الله» is not correct. Those individuals who consider it permissible to say any words other than «بسم الله» do so without evidence and in opposition to the aforementioned hadith.
➋ If one forgets «بسم الله» and remembers it during ablution, then one should say it immediately; however, there is no need to repeat the ablution, because forgetfulness is excused.
➌ Intention (niyyah) is also necessary in ablution (wudu) and ritual bath (ghusl).

Benefits and Issues:
➊ «لَا وُضُوءَ» This statement indicates that reciting «بِسم الله» is a pillar (rukn) or condition (shart) for ablution (wudu), because from the apparent wording, what is negated is not perfection but rather validity and existence, as is generally intended by the construction of "la" for the negation of genus. However, Imam Ahmad rahimahullah says that nothing is established regarding this matter. Nevertheless, due to its various chains and numerous supporting narrations, Hafiz Ibn al-Salah, Ibn Kathir, and Allamah Iraqi rahimahumullah and others have declared it hasan (good). The great contemporary scholar Allamah Albani rahimahullah has also graded it as hasan. Therefore, reciting it is Sunnah, so every person performing ablution should recite «بسم الله» at the beginning of ablution.

➋ According to the three Imams, reciting "Bismillah" at the beginning of ablution is Sunnah. According to Dawud al-Zahiri, reciting "Bismillah" at the start of ablution is obligatory (wajib). The statement of Ishaq ibn Rahwayh is that whoever deliberately does not recite "Bismillah," his ablution is not valid, and this is the preferred opinion.

Hadith Narrator: SR Sayyiduna Sa'id ibn Zayd radi Allahu anhu ER: Sa'id ibn Zayd ibn Amr ibn Nufayl al-Adawi al-Qurashi. His kunyah is Abu'l-A'war. He is among those ten most fortunate Companions radi Allahu anhum who were given the glad tidings of Paradise in this world by the blessed tongue of the Messenger of Allah sallallahu alayhi wa sallam. He is an early convert to Islam. Among his wives was Fatimah bint al-Khattab radi Allahu anha, the sister of Sayyiduna Umar radi Allahu anhu. This husband and wife were the means and cause for Sayyiduna Umar radi Allahu anhu entering the fold of Islam. He participated in all the battles except the Battle of Badr. He passed away in 51 AH and was buried in the Baqi' cemetery.