Translation:Shulchan Aruch/Orach Chaim/436

The Laws Applying to One Who Sets out on a Sea Voyage or Journeys by Caravan:

1. If one sets out on a journey from land to the sea, or in a caravan, and he did not leave anyone at home that could check for him within 30 days, he must check [and he does not make the blessing "al biur chametz"] (Kol Bo). Before 30 days, he does not need to check and when Pesacdh arrives it is nullified. (Tur). If one intends to return before Passover, he must check for Chametz, and afterward he may go out, due to concerns lest he might return on the eve of Passover between twilight periods and will not have time to burn [the leavened bread]. Similarly, one who makes his home a storage place within thirty days is in need of checking, and afterward he may store within it. Before thirty days, if one intends to clear it out before Passover, he must check for chametz, and afterward he may clear it out. But if he does not intend to clear it out before Passover, he does not need to check for chametz.Rema: And a wheat storehouse that has leavened wheat at the bottom of the pit: if the storehouse is made thirty days before Passover, there is no need to burn it (the chametz); rather, one may nullify it in his heart, which is sufficient. However, after Passover, when clearing out the storehouse, it is prohibited to derive benefit from those wheat grains. And if there is no known leavened bread there, only doubt, it is permitted to sell what was stored so it is concluded together. (Responsa of Rashba, Section 70)

2. Some say that before thirty days, when there is no need to inspect, that is when he does not intend to return during Passover, even if his intention is to return before or after Passover, he does not need to inspect, since it is before thirty days, (and when Passover arrives, he should nullify it). But if his intention is to return during Passover, he must inspect, even from Rosh Hashanah. And if he forgets and does not inspect, he should nullify it when Passover arrives and should not recite a blessing upon nullification. (Also, his wife should inspect and nullify in their house, lest he forget to nullify in the place where he is)." (Kol Bo)

3. If an Israelite who leaves a Gentile's house within thirty days and enters another house in the same city or goes to another city, he does not need to burn it in the Gentile's house, for he fulfills the obligation of removal in the other house. However, if he sets out at sea or went in a caravan and does not enter a Jewish home for Passover, some say that the obligation of removal (and burning) applies to him since it is within thirty days, and he must burn at the Gentile's house he is leaving in order to fulfill the obligation of removal (even though the Gentile will enter the house during Passover, and some say he does not need to when a Gentile enters). (Tur)