Whoever performs the Fajr prayer is under the protection of Allah, so none of you should harm the one under the protection of Allah in any way, for whoever does that will be definitely overtaken by the wrath of Allah and will then be thrown on his face in Hellfire [Muslim]

"«مَنْ صَلَّى صلاةَ الصُّبْحِ فهو في ذِمَّةِ اللهِ فلا يَطْلُبَنَّكُمُ اللهُ مِنْ ذِمَّتِهِ بِشَيْءٍ، فَإِنَّهُ مَنْ يَطْلُبْهُ مِنْ ذِمَّتِهِ بِشَيْءٍ يُدْرِكْهُ، ثُمَّ يَكُبُّهُ على وَجْهِهِ في نَارِ جَهَنَّمَ». [صحيح.] - [رواه مسلم.]"