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]. (ID)
App reference (ID): Book 13, Hadith 10 (ID)
Arabic/English book reference (ID): Book 13, Hadith 1385 (ID)