Hadith.1798 - It is narrated by Jamil ibn Darraj from Abu Abdullah عليه السلام that Imam عليه السلام said:
"Whoever visits his brother while fasting, then breaks his fast at his house without informing him of his fasting to gain favor, Allah سبحانه وتعالى will write for him the reward of fasting a full year."
The compiler of this book—may Allah سبحانه وتعالى have mercy on him—said: "This applies to both obligatory and recommended fasts."
My father - may Allah سبحانه وتعالى be pleased with him, said in his message to me: "If you intend to travel and wish to fulfill some of the recommended fasts in advance, then fast three days for the month in which you plan to depart."