In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Answering your question, the Fatwa Center at Islam Q & A, states:
Imam At-Tirmidhi narrated that Anas ibn Malik (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever prays to Allah for forty days in congregation, catching up with the first takbeer, he will be recorded as being free from two things: free from the Fire and free from hypocrisy.”
This hadith was classed as weak by At-Tirmidhi and a number of earlier scholars. However, some later scholars classed it as good, including al-Albani in Sahih At-Tirmidhi.
Almighty Allah knows best.