ما هو التثويب وما هو حكمه في صلاة الفجر؟

Tathwib is the pronouncement by the mu'adhdhin (caller to prayer) after saying "Hayya 'ala al-falah" (Hasten to success): "As-salatu khayrun min an-nawm" (Prayer is better than sleep) twice. This is a Sunnah (prophetic tradition) in the adhan (call to prayer) for the Fajr (dawn) prayer. This is supported by the narration of An-Nasa'i from Abu Mahdhurah, and it is the view of the majority of jurists. As for Abu Hanifa, he held that tathwib involves saying: "Hayya 'ala as-salat" (Hasten to prayer) twice, and "Hayya 'ala al-falah" (Hasten to success) twice, between the adhan and the iqamah (second call to prayer) for Fajr.