Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates: the Prophet (peace and blessings be upon him) said: "When one of you intends to travel, he should greet his brothers with salam, for they will add good to his supplication through their supplications."
Imam al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator, Yahya bin al-Ala' al-Bajali, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحج / 5284