Is it obligatory to shorten and combine prayers while traveling for someone who is still on the move and has not yet intended to take up residence?

If a traveler does not intend to stay in a place for four days, he may shorten the four-rak'ah prayers and avail himself of all other travel concessions, even if he stays for more than four days. However, if he intends to stay for four days or more, the ruling of travel ceases, and he should not shorten the prayers. Shortening the four-rak'ah prayers to two rak'ahs is a Sunnah (recommended) for the traveler, not obligatory. It is better for the traveler not to combine prayers as long as he has dismounted, but there is no harm if he does combine them.