What phrase suffices for the Basmalah in purification, and when must it be said?

Primary text

The sufficient utterance for the Basmalah is 'Bismillah,' and no other phrase can substitute it, similar to the required utterance during ritual slaughter or upon eating and drinking. Its proper position is after the intention (*niyyah*) but before all the physical actions of purification. This is because the utterance is an obligatory statement for the purification, so it follows the intention to encompass all its obligations, and it precedes the physical acts so that the utterance covers all of them, analogous to pronouncing the name at the time of slaughter.