Prayer: Performing Prayer Acts in Close Succession
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1100
One must perform the [parts of the] prayer in close succession, i.e. he must perform acts such as rukūʿ, sujūd, and tashahhud one after the other, and he must say those things that are said in prayers one after the other in a normal manner. If a person delays between the acts to the extent that it cannot be said he is performing prayers, his prayer is invalid.