Finding out the Direction of the Qibla After Performing the Salaah

Q: Salaah- 648: Discussing facing the Qibla, the Mujtabaa publication of Behisti Zewar (Vol.2 Pg.17) and Behisti Thamar (Vol.1 Pg.66) state that when the Qibla is unknown and there is none to ask, one may apply one's mind to determine the direction and perform salaah in the direction that the heart is satisfied with. The salaah will not be valid without applying one's mind even if it is established afterwards that the direction was correct.
However, the Akhtari publication of Behisti Zeutar (Vol.2 Pg.16) states that if it is established afterwards that the direction was correct, then the salaah will be valid. Which of the two books are correct?

Answer: The ruling as stated in the Akhtari publication is correct. Nurul Idhaa (Pg.405) states that if the salaah is performed without applying one's mind and it is established after completion that the direction was correct, the salaah will be valid. However. if this is established during the course of the salaah, the salaah will be nullified (just as the salaah of one who performed Tayammum will be nullified when he has access to water during the salaah). And Allaah knows best what is most correct.

Fatawa Rahimiyyah vol.2