Sahih Muslim , Book 4, Hadith 1277 (USC-MSA) ⓘ
'Abdullah narrated it on the authority of his father Yahya: Knowledge cannot be acquired with sloth.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، قَالَ أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ يَحْيَى بْنِ أَبِي كَثِيرٍ، قَالَ سَمِعْتُ أَبِي يَقُولُ، لاَ يُسْتَطَاعُ الْعِلْمُ بِرَاحَةِ الْجِسْمِ .
also referenced under: Book 5, Hadith 224 (In-Book) & Hadith 612 (Reference)