And if a person fears that an enemy will overtake him were he to fall behind his companions, so he performs the prayer of fear, and it later turns out that the road was actually safe, he is not required to repeat the prayer.

If fear arises—or subsides—while he is already praying, he should switch to the appropriate form and build upon what he has already performed.

The worshipper may advance and retreat for a legitimate purpose, and the prayer is not nullified by the length such movement causes.

Likewise, when there is a need, it is permissible to carry something ritually impure, and he does not have to repeat the prayer.