The Messenger of Allah said: "If you see a man frequenting the mosques, then bear witness to his faith. Allah says: 'The mosques of Allah shall be maintained only by those who believe in Allah and the Last Day. '"
Sunan Ibn Majah Book 4, Hadith 68
← Previous Hadith "We performed the Maghrib (prayer) with the Messenger of Allah, then those who went back went back, and those who stayed, stayed. Then the Messenger of Allah came back in a hurry, out of breath, with his garment pulled up to his knees, and said: 'Be of good cheer, for your Lord has opened one of the gates of heaven and is boasting of you before the angels, saying: "Look at My slaves; they have fulfilled one obligatory duty and are awaiting another."

Sunan Ibn Majah Book 4, Hadith 67 Next Hadith → “I heard Abu Humaid As-Sa’idi say: ‘When the Messenger of Allah (ﷺ) stood up for prayer, he would face the prayer direction, raise his hands, and say: “Allahu Akbar (Allah is Most Great).”

Sunan Ibn Majah Book 5, Hadith 1