that the Messenger of Allah ﷺ said: "Whoever goes out seeking knowledge, then he is in Allah's cause until he returns."

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ خَرَجَ فِي طَلَبِ الْعِلْمِ فَهُوَ فِي سَبِيلِ اللَّهِ حَتَّى يَرْجِعَ