After having intercourse with the wife, how should I offer Fajr prayers on time as at times it is not possible to take the bath during the night? How should we prepare ourselves for Fajr prayers or can it be offered immediately when you wake up in the morning, take your bath and then complete your Fajr prayers?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Allah Says (what means): {Indeed, prayer has been decreed upon the believers a decree of specified times.} [Quran 4:103]
The Prophet said: “The most beloved deed to Allah is performing the Prayer at its prescribed fixed time.” [Al-Bukhari and Muslim]
Delaying a Prayer till its time ends is not permissible. Doing so is one of the characteristics of hypocrites. Allah Says while describing the hypocrites (what means): {[But] who are heedless of their prayer.} [Quran 107:5]
Therefore, you are obliged to perform the Fajr Prayer at its particular time. You may use the available tools to help you for waking up for Fajr Prayer, such as an alarm clock or asking someone to wake you up.
Anyway, it is not permissible for you to intentionally delay the Fajr Prayer from its fixed time.
For more benefit on the ruling on abandoning the prayer or delaying it, please refer to Fataawa 384457, 377344, 88016, 84178, 83565, 87587, 90926, 88690 and 84403.
Allah knows best.
You can search for fatwa through many choices