My uncle told me that if you dont wait until sunrise after fajr prayer you will be punished is this true?
Extracted from this link:
It is mustahabb to stay in the mosque after Fajr prayer until the sun rises, because this is what the Prophet (SAW) and his companions did, and because there is great reward in that.
Muslim (670) narrated from Jaabir ibn Samurah that when the Prophet (SAW) had prayed Fajr, he would sit in his prayer place until the sun had risen properly.
Muslim also narrated (670) that Sammaak ibn Harb said: I said to Jaabir ibn Samurah: Did you sit with the Messenger of Allah (SAW)? He said: Yes, frequently. He would not get up from the place in which he had prayed Fajr until the sun had risen, and when the sun had risen he would get up. They used to chat and talk about matters of the Jaahiliyah, and they would laugh but he smiled.
Al-Tirmidhi narrated that
Anas ibn Maalik (RA) said: The Messenger of Allah (SAW) said: “Whoever prays Fajr in congregation then sits remembering Allah until the sun rises, then prays two rak’ahs, will have a reward like that of Hajj and ‘Umrah.” He said: The Messenger of Allah (SAW) said: “In full, in full, in full.”
This hadeeth was classed as hasan by al-Albaani in Saheeh al-Tirmidhi.
Mustahabb actions are those whose status of approval in Islamic law falls between mubah (neither encouraged nor discouraged) and wajib (compulsory). One definition is "duties recommended, but not essential; fulfilment of which is rewarded, though they may be neglected without punishment". The opposite of mustahabb is makruh (discouraged).