Saeed bin al-Musayyib narrates: When you find some people in the state of bowing (ruku‘), then say the takbeer and join them in ruku‘, so that one takbeer will suffice for you as both the opening takbeer (takbeer al-tahrimah) and the takbeer for going into ruku‘. This statement is also narrated from Saeed bin al-Musayyib: He said: Whoever forgets to say the opening takbeer (takbeer al-tahrimah) at the beginning of the prayer, then says the takbeer for going into ruku‘, then that will suffice for him.