(18) باب مَنْ قَالَ يُصَلِّي بِكُلِّ طَائِفَةٍ رَكْعَةً وَلاَ يَقْضُونَ
Narrated Ibn 'Abbas:
Allah, the Exalted, prescribed prayer for you, through the tongue of your Prophet (ﷺ), four rak'ahs while resident, two rak'ahs while travelling and one rak'ah in time of danger. (IT)
Reference (IT): Sunan Abi Dawud 1247 (IT)
In-book reference (IT): Book 4, Hadith 50 (IT)
English translation (IT): Book 4, Hadith 1242 (IT)