Anas (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "He who goes forth in search of knowledge is considered as struggling in the Cause of Allah until he returns."[At- Tirmidhi]. (JA)
App reference (JA): Book 13, Hadith 10 (JA)
Arabic/English book reference (JA): Book 13, Hadith 1385 (JA)