The hadith regarding the issue is as follows:

Abu Hurayra (may Allah be pleased with him) narrates: "the Messenger of Allah said, ‘No prayer is harder for the hypocrites than the morning and the night prayers and if they knew the reward for these prayers at their respective times, they would certainly present themselves in the mosques even if they had to crawl." The Prophet added, "Certainly I decided to order the muadhdhin to pronounce adhan and order a man to lead the prayer and then take a fire flame to burn all those who had not left their houses so far for the prayer along with their houses.’” (Bukhari, Adhan 29, Husumat 5, Ahkam 52; Muslim, Masajid 252, (651); Muwatta, Salatu'l-Jama'a 3, (1, 129-130); Abu Dawud, Salat 47, (548, 549); Tirmidhi, Salat 162, (217); Nasai, Imamah 49, (2, 107).

Since the word ‘men’ is used in the hadith, women and children are regarded to be exempt from it. Besides, since praying in congregation is twenty-five or according to another narration twenty-seven times more virtuous than praying at home or somewhere else alone, our Prophet encouraged praying in congregation with this hadith.    

There are many hadiths mentioning the importance of praying in congregation. As it is understood from those hadiths, the threat was uttered by the Prophet because he does not want his ummah to be deprived of the reward of praying in congregation and he wants to call people who do not pray in congregation to the mosque and hence to praying in congregation. He expressed the importance of praying in congregation like that.

The hadith should be evaluated in the form of encouraging people to pray in congregation and threatening those who abandon praying in congregation. The Prophet did not utter those words because he wanted to burn the houses of people. As a matter of fact, if he wanted to do so, he could have done it. That is, he preferred those words in order to express the importance of the issue. We also use different expressions for the important things in our daily lives.