Q: Is it permissible to pray Tahayatul Wudhu (the optional prayers after ablution) and Tahayatul Masjid (optional prayers on entering a Masjid) at Fajr and Asr prayer time?
A: It will be Makrooh at Fajr time and after the Fardh of Asr has been performed. It will not be Makrooh before the Fardh of Asr. No Nafl should be performed from the time that Fajr starts (Subuh Saadiq) till approximately 15 minutes after sunrise. The only Salaah performed during this time is the two Sunnah and two Fardh of Fajr.
Moulana Yusuf Laher