Is prayer in congregation valid, and is the one who performs it rewarded with the reward of praying in a distant mosque, if his leaving his home was not solely for performing prayer in that mosque, but rather for performing prayer and purchasing something or attending a knowledge lesson from a place near the mosque, with his intention varying before leaving the house? And what is the connection of this to the Hadith: "A man's prayer in congregation is multiplied twenty-five times over his prayer in his home and in his market..."? And what is its connection to the issue of "one who performs ablution intending to cool down and clean himself, and to remove ritual impurity"?