What is the ruling on the shortened prayer (Salat al-Qasr)?

Qasr is the shortening of the four-rak'ah prayer to two rak'ahs during long journeys, which is a distance of two days by heavy loads (approximately 83 km). It is a condition that the journey must be permissible. Qasr is a concession and is better than performing the prayer in full. A traveler shortens the prayer after departing from the houses of his town and continues to shorten it until he reaches his destination, or intends to stay four days or more, or if he has a wife in the town he traveled to. If he intends to stay less than four days, he shortens the prayer. If he passes through his homeland and stays for a day or more, he performs the prayer in full. It is permissible for the traveler to perform supererogatory prayers, both absolute and regular (Sunnah) ones.