(a) Al-Aswad bin Qays narrates from his father that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) saw a man dressed for travel, and he heard him saying: Were it not that today is Friday, I would have set out on my journey. So Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: Go, for the Friday prayer does not hold anyone back from a journey.
(b) Al-Thawri narrates from al-Aswad that he saw a man who intended to travel on Friday and was waiting for the Friday prayer, and Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said the same thing to him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5654