with swords, whether you are riding, running, or walking. If you are able, then [pray] two rak'ahs; otherwise, [pray] one rak'ah, signaling with your head however you may be facing.

Yahya said: And it reached me that if the matter is more intense than that, he should say the takbir four times.

Muhammad said: His saying: "On foot or riding" means: then pray while on foot or riding. "Rijalan" (on foot) is the plural of "rajil" (foot-traveler), just as they said: "sahib" (companion) and "sahab" (companions). The fear here is [based] upon certainty, not conjecture. "And when you are secure, then remember Allah as He has taught you that which you did not know," meaning: pray to Allah, the Exalted. [Verses 240-242]