Yahya said: Abu Umayya ibn Ya'la narrated to me, from Qatada, from Abdullah ibn Mas'ud, who said: "We used to write: 'Bi-ismika Allahumma' (In Your name, O Allah) for a time. When the verse: 'Say: Call upon Allah or call upon the Most Gracious (al-Rahman)' [Al-Isra: 110] was revealed, we wrote: 'Bi-ism Allah al-Rahman' (In the name of Allah, the Most Gracious). Then when the verse: 'Indeed, it is from Solomon, and indeed, it is: In the name of Allah, the Most Gracious, the Most Merciful' [Al-Naml: 30] was revealed, we wrote: 'Bi-ism Allah al-Rahman al-Rahim' (In the name of Allah, the Most Gracious, the Most Merciful)."
Yahya: Al-Hasan ibn Dinar narrated to us, from Al-Hasan al-Basri, who said: "'Bi-ism Allah al-Rahman al-Rahim' (In the name of Allah, the Most Gracious, the Most Merciful) was not revealed in any part of the Qur'an except in this verse: 'Indeed, it is from Solomon...'. He (the reciter) makes it the opening of the recitation when he recites."
Yahya: Abu al-Ashhab narrated to me, from Al-Hasan, that he said: "These two names are among the names of Allah which are forbidden; no one among the creation can claim them: Allah and Al-Rahman."
Muhammad said: It is said that the one who brings the 'ba' (the letter 'b' in 'Bi-ism') in 'Bi-ism Allah' carries the meaning of commencement; as if you have said: 'I begin in the name of Allah.'