The Messenger of Allah ﷺ said, "The supplication that receives the swiftest response is the supplication of one absent person for another."
حدثنا أحمد بن عمرو بن السرح حدثنا ابن وهب حدثني عبد الرحمن بن زياد عن أبي عبد الرحمن
أن رسول الله ﷺ قال إن أسرع الدعاء إجابة دعوة غائب لغائب
[Its chain is daif] Reported by Tirmidhi, in "Righteousness and Kinship," chapter, "What Has Been Said About a Man's Supplication for His Brother in His Absence," no. 1980, from the hadith of Abdul-Rahman bin Ziyad Afriqi, with this wording. He said, "Gharib..." and Afriqi is considered weak in hadith.