2:239
فَاِنْ خِفْتُمْ فَرِجَالًا اَوْ رُكْبَانًاۚ فَاِذَٓا اَمِنْتُمْ فَاذْكُرُوا اللّٰهَ كَمَا عَلَّمَكُمْ مَا لَمْ تَكُونُوا تَعْلَمُونَ
Fain khiftum farijalan aw rukbanan faitha amintum faothkuroo Allaha kama AAallamakum ma lam takoonoo taAAlamoona
Translations
And if you fear [an enemy, then pray] on foot or riding. But when you are secure, then remember Allah [in prayer], as He has taught you that which you did not [previously] know
Saheeh International
And if ye go in fear, then (pray) standing or on horseback. And when ye are again in safety, remember Allah, as He hath taught you that which (heretofore) ye knew not
Marmaduke Pickthall