Originally, two rakʿat were prescribed in every prayer. When the Prophet ﷺ migrated (to Medina) four rakʿat were enjoined, while the journey prayer remained unchanged(i.e. two rakʿat).
فُرِضَتِ الصَّلاَةُ رَكْعَتَيْنِ ثُمَّ هَاجَرَ النَّبِيُّ ﷺ فَفُرِضَتْ أَرْبَعًا وَتُرِكَتْ صَلاَةُ السَّفَرِ عَلَى الأُولَى
"The prayer of the resident was enjoined on the tongue of your Prophet ﷺ, four (rak'ahs), and the prayer of the traveler is two rak'ahs, and the prayer of fear is one rak'ah."
فُرِضَتْ صَلاَةُ الْحَضَرِ عَلَى لِسَانِ نَبِيِّكُمْ ﷺ أَرْبَعًا وَصَلاَةُ السَّفَرِ رَكْعَتَيْنِ وَصَلاَةُ الْخَوْفِ رَكْعَةً
"The prayer of the resident was enjoined on the tongue of your Prophet ﷺ, four (rak'ahs), and the prayer of the traveler is two rak'ahs, and the prayer of fear is one rak'ah." (Using translation from Nasāʾī 1441)
«فُرِضَتْ صَلَاةُ الْحَضَرِ عَلَى لِسَانِ نَبِيِّكُمْ أَرْبَعًا وَصَلَاةُ السَّفَرِ رَكْعَتَيْنِ وَصَلَاةُ الْخَوْفِ رَكْعَةً»
"The prayer of the resident was enjoined on the tongue of your Prophet ﷺ, four (rak'ahs), and the prayer of the traveler is two rak'ahs, and the prayer of fear is one rak'ah." (Using translation from Nasāʾī 1441)
«فُرِضَتْ صَلَاةُ الْحَضَرِ عَلَى لِسَانِ نَبِيِّكُمْ ﷺ أَرْبَعًا وَصَلَاةُ السَّفَرِ رَكْعَتَيْنِ وَصَلَاةُ الْخَوْفِ رَكْعَةً»